implementer.cpp: In function ‘int main()’:
implementer.cpp:22:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   22 |         scanf("%d", &n);
      |         ~~~~~^~~~~~~~~~
answer.code:7:24: error: redefinition of ‘const int N’
    7 | const int n = 1 << 10, N = (1 << 21) | 1;
      |                        ^
answer.code:5:11: note: ‘const int N’ previously defined here
    5 | const int N = 200005;
      |           ^
answer.code: In function ‘void init(int)’:
answer.code:12:9: error: ‘u’ was not declared in this scope
   12 |     lep(u, 1, n) {
      |         ^
answer.code:12:5: error: ‘lep’ was not declared in this scope
   12 |     lep(u, 1, n) {
      |     ^~~
answer.code:28:9: error: ‘a’ was not declared in this scope
   28 |     lep(a, 0, lim) {
      |         ^
answer.code:32:9: error: ‘i’ was not declared in this scope
   32 |     lep(i, 2, N - 1) {
      |         ^
answer.code: In function ‘int inv(int)’:
answer.code:41:12: error: ‘mul’ was not declared in this scope; did you mean ‘fmul’?
   41 |     return mul(u + mod, iv[pot[a] + b * u]);
      |            ^~~
      |            fmul