answer.code:1:1: error: ‘s64’ does not name a type
    1 | s64 wn[N << 2], rev[n << 2];
      | ^~~
answer.code: In function ‘int NTT_init(int)’:
answer.code:6:9: error: ‘rev’ was not declared in this scope
    6 |         rev[i] = (rev[i >> 1] >> 1) | ((i & 1) << (step - 1));
      |         ^~~
answer.code:7:17: error: ‘G’ was not declared in this scope
    7 |     int g = bin(G, (MOD - 1) / n, MOD);
      |                 ^
answer.code:7:21: error: ‘MOD’ was not declared in this scope
    7 |     int g = bin(G, (MOD - 1) / n, MOD);
      |                     ^~~
answer.code:7:13: error: ‘bin’ was not declared in this scope
    7 |     int g = bin(G, (MOD - 1) / n, MOD);
      |             ^~~
answer.code:8:5: error: ‘wn’ was not declared in this scope; did you mean ‘n’?
    8 |     wn[0] = 1;
      |     ^~
      |     n
answer.code: At global scope:
answer.code:13:6: error: variable or field ‘NTT’ declared void
   13 | void NTT(s64 a[], int n, int f) {
      |      ^~~
answer.code:13:10: error: ‘s64’ was not declared in this scope
   13 | void NTT(s64 a[], int n, int f) {
      |          ^~~
answer.code:13:19: error: expected primary-expression before ‘int’
   13 | void NTT(s64 a[], int n, int f) {
      |                   ^~~
answer.code:13:26: error: expected primary-expression before ‘int’
   13 | void NTT(s64 a[], int n, int f) {
      |                          ^~~