answer.code: In function ‘long long int lcmbignumber(long long int, long long int)’:
answer.code:212:16: error: ISO C++ forbids declaration of ‘x’ with no type [-fpermissive]
  212 |     for (auto& x : ma)
      |                ^
answer.code:212:20: warning: range-based ‘for’ loops only available with ‘-std=c++11’ or ‘-std=gnu++11’
  212 |     for (auto& x : ma)
      |                    ^~
answer.code:212:20: error: forming reference to reference type ‘std::map<long long int, long long int>&’
answer.code:213:32: error: request for member ‘first’ in ‘x’, which is of non-class type ‘int’
  213 |         ans = mul(fast_power(x.first, x.second), ans);
      |                                ^~~~~
answer.code:213:41: error: request for member ‘second’ in ‘x’, which is of non-class type ‘int’
  213 |         ans = mul(fast_power(x.first, x.second), ans);
      |                                         ^~~~~~
answer.code: In function ‘std::string addtwostringasnumber(std::string&, std::string&)’:
answer.code:310:15: error: ‘to_string’ was not declared in this scope
  310 |         out = to_string(carry) + out;
      |               ^~~~~~~~~