View Compilation Error

0_0_21885208_13520.cpp: In function 'int main()':
0_0_21885208_13520.cpp:117:12: error: 'st' was not declared in this scope
         if(st==en) k++;
            ^
0_0_21885208_13520.cpp:117:16: error: 'en' was not declared in this scope
         if(st==en) k++;
                ^