/in/foo.cc:7:11: error: '::main' must return 'int'
 void main()
           ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:10:16: warning: format '%ld' expects argument of type 'long int*', but argument 2 has type 'int*' [-Wformat=]
  scanf("%ld",&m);
                ^