/in/foo.cc: In function 'int main()':
/in/foo.cc:7:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k,n,m,jz=0;
          ^
/in/foo.cc:7:16: warning: unused variable 'jz' [-Wunused-variable]
  int i,j,k,n,m,jz=0;
                ^~