/in/foo.c: In function 'main':
/in/foo.c:4:14: warning: unused variable 'x' [-Wunused-variable]
  int m,n,i,j,x;
              ^
/in/foo.c:4:12: warning: unused variable 'j' [-Wunused-variable]
  int m,n,i,j,x;
            ^