View Compilation Error

0_0_34911100_11866.cpp: In function 'int main()':
0_0_34911100_11866.cpp:3:21: error: 'a' was not declared in this scope
  while(scanf("%d%d",a,b)!=EOF){
                     ^
0_0_34911100_11866.cpp:3:23: error: 'b' was not declared in this scope
  while(scanf("%d%d",a,b)!=EOF){
                       ^