View Compilation Error

0_0_21913226_25711.cpp: In function 'int main()':
0_0_21913226_25711.cpp:76:16: error: 'n' was not declared in this scope
     while(cin>>n>>m)
                ^
0_0_21913226_25711.cpp:76:19: error: 'm' was not declared in this scope
     while(cin>>n>>m)
                   ^