View Compilation Error

0_0_38797951_18227.cpp: In function 'int main()':
0_0_38797951_18227.cpp:22:9: error: 'cout' was not declared in this scope
   22 |         cout << "3 1\n";
      |         ^~~~
0_0_38797951_18227.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)