View Compilation Error

0_0_28576240_14202.cpp: In function 'int main()':
0_0_28576240_14202.cpp:15:16: error: 'a' was not declared in this scope
     while(cin>>a>>b){
                ^
0_0_28576240_14202.cpp:15:19: error: 'b' was not declared in this scope
     while(cin>>a>>b){
                   ^