answer.code: In function ‘int main()’:
answer.code:8:16: error: ‘r’ was not declared in this scope
    8 | scanf("%d%d", &r, &c);
      |                ^
answer.code:8:20: error: ‘c’ was not declared in this scope; did you mean ‘tc’?
    8 | scanf("%d%d", &r, &c);
      |                    ^
      |                    tc
answer.code:5:13: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
    5 | int t; scanf("%d", &t);
      |        ~~~~~^~~~~~~~~~
answer.code:12:6: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   12 | scanf("%s", s+1);
      | ~~~~~^~~~~~~~~~~