View Compilation Error

0_0_33793026_13216.cpp: In function 'int main()':
0_0_33793026_13216.cpp:50:13: error: 'n' was not declared in this scope
  while(cin>>n>>m)
             ^
0_0_33793026_13216.cpp:50:16: error: 'm' was not declared in this scope
  while(cin>>n>>m)
                ^