View Compilation Error

0_0_34079007_29142.cpp: In function 'int main()':
0_0_34079007_29142.cpp:15:4: error: 'u' was not declared in this scope
    u--,v--;
    ^
0_0_34079007_29142.cpp:15:8: error: 'v' was not declared in this scope
    u--,v--;
        ^