View Compilation Error

0_0_30312918_2726.cpp: In function 'int main()':
0_0_30312918_2726.cpp:7:15: error: 'n' was not declared in this scope
  while ( cin>>n>>m){//无限输入多组数据 
               ^
0_0_30312918_2726.cpp:7:18: error: 'm' was not declared in this scope
  while ( cin>>n>>m){//无限输入多组数据 
                  ^