foo.cc: In function 'int main()':
foo.cc:56:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&t);
  ~~~~~^~~~~~~~~
foo.cc:59:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&n,&m);
   ~~~~~^~~~~~~~~~~~~~
foo.cc:61:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&c);
    ~~~~~^~~~~~~~~