/in/foo.cc: In function 'int main()':
/in/foo.cc:29:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scan(t);
         ^
/in/foo.cc:32:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scan(n);
          ^
/in/foo.cc:33:51: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   for(int i = 1;i<=n;++i)scanf("%d%d",&a[i],&b[i]);
                                                   ^