View Compilation Error

0_0_21549422_15755.cpp: In function 'int main()':
0_0_21549422_15755.cpp:27:16: error: 'u' was not declared in this scope
             if(u!=v)
                ^
0_0_21549422_15755.cpp:27:19: error: 'v' was not declared in this scope
             if(u!=v)
                   ^