View Compilation Error

0_0_38760316_610.cpp: In function 'void solve()':
0_0_38760316_610.cpp:44:5: error: 'cin' was not declared in this scope
   44 |     cin >> n;
      |     ^~~
0_0_38760316_610.cpp:45:5: error: 'memset' was not declared in this scope
   45 |     memset(h, -1, sizeof h);
      |     ^~~~~~
0_0_38760316_610.cpp:1:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
  +++ |+#include <cstring>
    1 | #define int long long
0_0_38760316_610.cpp:59:5: error: 'cout' was not declared in this scope
   59 |     cout << ans * qmi(n, mod - 2) % mod << endl;
      |     ^~~~
0_0_38760316_610.cpp:59:44: error: 'endl' was not declared in this scope
   59 |     cout << ans * qmi(n, mod - 2) % mod << endl;
      |                                            ^~~~
At global scope:
cc1plus.exe: error: '::main' must return 'int'