/in/foo.cc: In function 'int main()':
/in/foo.cc:41:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int n,m,k,x,y;scanf("%d",&n);
                              ^
/in/foo.cc:44:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d",&x,&k,&m);
                           ^
/in/foo.cc:48:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&y);
                  ^