foo.c: In function 'main':
foo.c:7:11: warning: format '%ld' expects argument of type 'long int *', but argument 2 has type 'long long int *' [-Wformat=]
  scanf("%ld%ld",&n,&m);
         ~~^     ~~
         %lld
foo.c:7:14: warning: format '%ld' expects argument of type 'long int *', but argument 3 has type 'long long int *' [-Wformat=]
  scanf("%ld%ld",&n,&m);
            ~~^     ~~
            %lld
foo.c:7:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%ld%ld",&n,&m);
  ^~~~~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务