View Compilation Error

0_0_39799129_341.cpp: In function 'bool check(std::string, std::string)':
0_0_39799129_341.cpp:14:20: error: expected ';' before 'while'
   14 |                 ++j
      |                    ^
      |                    ;
   15 |                 while(j<len){
      |                 ~~~~~