View Compilation Error

0_0_38500623_31333.cpp: In function 'std::string work()':
0_0_38500623_31333.cpp:7:18: error: 'a' was not declared in this scope
     for(auto &it:a){
                  ^
0_0_38500623_31333.cpp:11:27: error: 'now' was not declared in this scope
         fseufuihes+=start-now;
                           ^