View Compilation Error

0_0_39813566_16393.cpp: In function 'std::string sum(std::string, std::string)':
0_0_39813566_16393.cpp:53:24: error: expected '}' at end of input
   53 |         return longstr;
      |                        ^
0_0_39813566_16393.cpp:23:1: note: to match this '{'
   23 | {
      | ^