#include <mpi.h>
#include <iostream> 
using namespace std;
int main(int argc, char **argv) { 
int rank,size,len;
char host[MPI_MAX_PROCESSOR_NAME];
MPI_Status status;
MPI_Init( &argc, &argv); 
MPI_Comm_rank( MPI_COMM_WORLD, &rank ); 
MPI_Comm_size( MPI_COMM_WORLD, &size );
MPI_Get_processor_name(host,&len); 
int taskid=rank;
int numtask=size;
int partner;
if(size>0 && size%2==0){
cout<<"" <<"Zbyt mala liczba zadan"<<size<<endl;
return 0;
}
else{
if(taskid< numtask/2) {
partner=numtask/2 +taskid;
}
else if(taskid>=numtask/2){
partner = taskid-numtask/2;
}
} 

MPI_Finalize(); 
return 0; }