View Compilation Error

0_0_34760295_9176.cpp: In function 'int main()':
0_0_34760295_9176.cpp:5:23: error: 'a' was not declared in this scope
  while(~scanf("%d%d",&a,&b))
                       ^
0_0_34760295_9176.cpp:5:26: error: 'b' was not declared in this scope
  while(~scanf("%d%d",&a,&b))
                          ^