/in/foo.cc: In function 'int main(int, char**)':
/in/foo.cc:9:13: warning: right operand of comma operator has no effect [-Wunused-value]
     cin>>m,n;
             ^
/in/foo.cc:11:19: warning: 'n' may be used uninitialized in this function [-Wmaybe-uninitialized]
     for (int i=1;i<=n-1;i++){
                  ~^~~~~