answer.code: In function ‘void solve()’:
answer.code:58:12: error: missing template arguments before ‘f’
   58 |     vector f(n * 2 + 1, vector<int> (n * 2 + 1));
      |            ^
answer.code:59:12: error: missing template arguments before ‘ok’
   59 |     vector ok(n * 2 + 2, vector<int> (n * 2 + 2));
      |            ^~
answer.code:61:9: error: ‘ok’ was not declared in this scope
   61 |         ok[i][i] = 1;
      |         ^~
answer.code:67:13: error: ‘f’ was not declared in this scope
   67 |             f[i][j] = max(f[i + 1][j], f[i][j - 1]);
      |             ^
answer.code:71:21: error: ‘ok’ was not declared in this scope; did you mean ‘k’?
   71 |                  if(ok[i][j])
      |                     ^~
      |                     k
answer.code:78:25: error: ‘ok’ was not declared in this scope; did you mean ‘k’?
   78 |                     if(!ok[ll][rr])continue;
      |                         ^~
      |                         k
answer.code:85:38: error: ‘ok’ was not declared in this scope; did you mean ‘k’?
   85 |                     if(tmp > f[i][j])ok[i][j] = true;
      |                                      ^~
      |                                      k
answer.code:96:24: error: ‘f’ was not declared in this scope
   96 |         res = max(res, f[i][i + n - 1]);
      |                        ^