View Compilation Error

0_0_39153414_12299.cpp: In function 'int main()':
0_0_39153414_12299.cpp:7:28: error: 'EFO' was not declared in this scope; did you mean 'EIO'?
    7 |         while(cin>>a>>b != EFO){
      |                            ^~~
      |                            EIO