View Compilation Error

0_0_21850193_31686.cpp: In function 'int main()':
0_0_21850193_31686.cpp:12:20: error: 'u' was not declared in this scope
     scanf("%d %d",&u,&v);
                    ^
0_0_21850193_31686.cpp:12:23: error: 'v' was not declared in this scope
     scanf("%d %d",&u,&v);
                       ^