answer.code: In function ‘void solve()’:
answer.code:29:29: error: ‘gcd’ was not declared in this scope
   29 |     long long l = 1LL * a / gcd(a, c) * c;
      |                             ^~~
answer.code:28:10: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   28 |     scanf("%d%d%d%d%lld%lld", &a, &b, &c, &d, &v, &t);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
answer.code: In function ‘int main()’:
answer.code:39:21: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   39 |     int tcase; scanf("%d", &tcase);
      |                ~~~~~^~~~~~~~~~~~~~