answer.code: In function ‘int main()’:
answer.code:179:5: error: expected ‘;’ before ‘string’
  179 |     string s; s = rd();
      |     ^~~~~~
answer.code:179:17: error: incompatible types in assignment of ‘const string’ {aka ‘const std::__cxx11::basic_string<char>’} to ‘ll [2000000]’ {aka ‘long long int [2000000]’}
  179 |     string s; s = rd();
      |                 ^
answer.code:180:11: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  180 |     if (s == "insert") {
      |           ^
answer.code:189:18: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  189 |     } else if (s == "erase") {
      |                  ^
answer.code:199:18: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  199 |     } else if (s == "print") {
      |                  ^
answer.code:209:18: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  209 |     } else if (s == "copy") {
      |                  ^
answer.code:216:18: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  216 |     } else if (s == "cut") {
      |                  ^
answer.code:227:18: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  227 |     } else if (s == "paste") {
      |                  ^
answer.code:235:18: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  235 |     } else if (s == "undo") {
      |                  ^
answer.code:241:18: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  241 |     } else if (s == "redo") {
      |                  ^
answer.code:248:18: error: comparison between distinct pointer types ‘ll*’ {aka ‘long long int*’} and ‘const char*’ lacks a cast [-fpermissive]
  248 |     } else if (s == "serialize") {
      |                  ^