diff --git a/lab1/Makefile b/lab1/Makefile
new file mode 100644
index 0000000..aa7f0df
--- /dev/null
+++ b/lab1/Makefile
@@ -0,0 +1,35 @@
+GCC      = gcc
+MPI      = mpicc
+CFLAGS   = -O3 -fopenmp
+OMP_FLAG = -fopenmp
+RM       =  rm -rf
+
+
+EXE = pi_ser pi_omp pi_task pi_mpi
+
+all : $(EXE) 
+
+#.PHONY: all  clean purge
+
+
+pi_ser: pi_ser.o
+	$(GCC) $(CFLAGS) -o $@ $^
+
+pi_task: pi_task.o
+	$(GCC) $(CFLAGS) -o $@ $^
+
+pi_omp: pi_omp.o
+	$(GCC) $(CFLAGS) $(OMP_FLAG)  -o $@ $^
+
+pi_mpi: pi_mpi.o
+	$(MPI) $(CFLAGS) -o $@  $^
+
+%.o :%.c
+	$(GCC) $(CFLAGS) -c -o $@ $<
+
+
+clean:
+	$(RM) *.o
+
+purge: clean
+	$(RM) $(EXE)
diff --git a/lab1/README b/lab1/README
new file mode 100644
index 0000000..140ab0b
--- /dev/null
+++ b/lab1/README
@@ -0,0 +1,33 @@
+=============
+MESOCENTRE FC
+=============
+
+-------------------------LAB 1----------------------------
+
+Compute PI with numerical integration (Trapezoidal rule) of:
+
+       / 1
+      |    4
+      |   --------- dx
+      |    1 + x^2
+      / 0
+
+Provided solution
+-----------------
+- pi_ser    :  serial version
+- pi_task   :  parallel array task version
+- pi_omp    :  parallel OpenMP version
+- pi_mpi    :  parallel MPI version
+- pi_matlab : Matlab version
+
+Howto?
+------
+1- use Make to compile 
+2- submit jobs using SGE
+3- For matlab example :
+
+module load matlab
+matlab -nojvm -nodisplay  -nosplash -r 'Pi_matlab(100000000);exit'
+
+
+HF  
diff --git a/lab1/pi_matlab.m b/lab1/pi_matlab.m
new file mode 100644
index 0000000..c8433bd
--- /dev/null
+++ b/lab1/pi_matlab.m
@@ -0,0 +1,13 @@
+
+function pi = Pi_matlab( n )
+
+h = 1.0/n;
+pi = 0.0;
+
+for i=1:n
+  x = (i + 0.5)*h;
+  pi = pi+ (4.0/(1.0 + x*x));
+  end
+ pi=pi*h;
+ disp(pi)
+end
diff --git a/lab1/pi_mpi.c b/lab1/pi_mpi.c
new file mode 100644
index 0000000..e0f3299
--- /dev/null
+++ b/lab1/pi_mpi.c
@@ -0,0 +1,59 @@
+#include <stdio.h>
+#include <string.h>
+#include "mpi/mpi.h"
+#define N 100000000
+
+int main (int argc, char** argv)
+{
+    int rank;
+    int size;
+    long long int n;
+    long long int i;
+
+    double l_sum,total_sum, x, h;
+
+    MPI_Init(NULL, NULL);
+   
+    MPI_Comm_size(MPI_COMM_WORLD, &size);
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+    
+    n=N;
+
+    if(rank==0)
+    {
+        if(argc==2)
+        {
+         n = atoll(argv[1]);
+        }
+
+        printf("MPI version with process = %d\n", size);
+        printf("Number of intervals: %lld\n", n);
+    }
+
+
+  MPI_Bcast(&n, 1, MPI_INT, 0, MPI_COMM_WORLD);
+    
+
+    h = 1.0/n;
+
+    l_sum = 0.0;
+
+    for (i = rank; i < n; i += size)
+    {
+        x = (i + 0.5)*h;
+        l_sum += 4.0/(1.0 + x*x);
+    }
+
+    l_sum *= h;
+
+    MPI_Reduce(&l_sum,&total_sum,1,MPI_DOUBLE,MPI_SUM,0,MPI_COMM_WORLD);
+    
+    if(rank==0)
+    {
+        printf("Pi=%0.12g\n", total_sum);
+
+    }
+
+    MPI_Finalize();
+    return 0;
+}
diff --git a/lab1/pi_omp.c b/lab1/pi_omp.c
new file mode 100644
index 0000000..b3684b5
--- /dev/null
+++ b/lab1/pi_omp.c
@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <omp.h>
+
+#define N 100000000
+int main (int argc, char** argv)
+{
+    long long int n;
+    long long int i;
+
+    double l_sum, x, h;
+
+    n=N;
+
+    if(argc==2)
+    {
+        n=atol(argv[1]);
+    }
+
+
+    h = 1.0/n;
+
+    l_sum = 0.0;
+
+#pragma omp parallel for private(i,x) reduction(+:l_sum)    
+    for (i = 0; i < n; i ++)
+    {
+        x = (i + 0.5)*h;
+        l_sum += 4.0/(1.0 + x*x);
+    }
+
+    l_sum *= h;
+
+    printf("N=%lld,PI=%0.12g\n",n, l_sum);
+
+    return 0;
+}
diff --git a/lab1/pi_ser.c b/lab1/pi_ser.c
new file mode 100644
index 0000000..28ed7b5
--- /dev/null
+++ b/lab1/pi_ser.c
@@ -0,0 +1,35 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define N 100000000
+int main (int argc, char** argv)
+{
+    long long int n;
+    long long int i;
+
+    double l_sum, x, h;
+
+    n=N;
+
+    if(argc==2)
+    {
+        n=atol(argv[1]);
+    }
+
+
+    h = 1.0/n;
+
+    l_sum = 0.0;
+    
+    for (i = 0; i < n; i ++)
+    {
+        x = (i + 0.5)*h;
+        l_sum += 4.0/(1.0 + x*x);
+    }
+
+    l_sum *= h;
+
+    printf("N=%lld, PI = %0.12g\n",n ,l_sum);
+
+    return 0;
+}
diff --git a/lab1/pi_task.c b/lab1/pi_task.c
new file mode 100644
index 0000000..6298901
--- /dev/null
+++ b/lab1/pi_task.c
@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define N 100000000
+
+int main (int argc, char** argv)
+{
+    int task_id;
+    int total_tasks;
+    long long int n;
+    long long int i;
+
+    double l_sum, x, h;
+
+    n=N;
+
+    if(argc<3)
+    {
+        fprintf(stderr,"Usage : %s task_id total_tasks [n]\n",argv[0]);
+        exit(0);
+    }
+
+    task_id = atoi(argv[1]);
+    total_tasks = atoi(argv[2]);
+    
+    if(argc==4)
+    {
+        n = atoll(argv[3]);
+    }
+
+    fprintf(stderr, "task_id=%d total_tasks=%d n=%lld\n", task_id, total_tasks, n);
+
+    h = 1.0/n;
+
+    l_sum = 0.0;
+
+    for (i = task_id; i < n; i += total_tasks)
+    {
+        x = (i + 0.5)*h;
+        l_sum += 4.0/(1.0 + x*x);
+    }
+
+    l_sum *= h;
+
+    printf("Pi=%0.12g\n", l_sum);
+
+    return 0;
+}