Main.cpp: In function 'int main()':
Main.cpp:31:11: warning: format '%i' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wformat=]
   31 |  printf("%i\n",s.size());
      |          ~^    ~~~~~~~~
      |           |          |
      |           int        std::vector<int>::size_type {aka long unsigned int}
      |          %li
Main.cpp:15:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     scanf("%i",&n);
      |     ~~~~~^~~~~~~~~
Main.cpp:18:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |   scanf("%i%i",&a[i].fi,&a[i].se);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~