View Compilation Error

0_0_16034058_10925.cpp: In function 'int main()':
0_0_16034058_10925.cpp:4:22: error: 'a' was not declared in this scope
  while(scanf("%d%d",&a,&b)|=EOF)
                      ^
0_0_16034058_10925.cpp:4:25: error: 'b' was not declared in this scope
  while(scanf("%d%d",&a,&b)|=EOF)
                         ^