View Compilation Error

0_0_38797702_27306.cpp: In function 'int main()':
0_0_38797702_27306.cpp:38:17: error: 'cout' was not declared in this scope
   38 |                 cout << res << '\n';
      |                 ^~~~
0_0_38797702_27306.cpp:4:1: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
    3 | #include <algorithm>
  +++ |+#include <iostream>
    4 | #define rep(i,j,k) for(int i=(j);i<=(k);++i)