/in/foo.cc: In function 'int main()':
/in/foo.cc:39:10: warning: unused variable 'c' [-Wunused-variable]
  for(int c,i=1;i<=n;i++)
          ^
/in/foo.cc:46:10: warning: unused variable 's' [-Wunused-variable]
  for(int s,u,x0,y0,x,y,i=1;i<=m;i++)
          ^