foo.cc: In function 'int main()':
foo.cc:32:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d%d",&m,&fm,&r,&c);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:33:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i=1;i<=r;i++) scanf("%d%d",&b[i],&p[i]);
                           ~~~~~^~~~~~~~~~~~~~~~~~~~