问在使用scanf()函数时遇到问题

EN

int xPos, yPos;    
while(1)
{
        printf("Enter two integers: ");
        if(scanf("%d %d", &xPos, &yPos) == 2)
        {
            printf("success \n");
        }
        else
        {
            printf("fail");
        }

}

Enter two integers: 4 4
success
Enter two integers: 13
fail
enter two integers: sda asd
fail

Enter two integers: 4 4
success
Enter two integers: 13
5 (it goes onto a new line for me and I have to enter something else to make it keep going) 
fail
Enter two integers: sda asd
Enter two integers:Enter two integers:Enter two integers:Enter two integers:Enter two integers:Enter two integers:Enter two integers:Enter two integers:Enter two integers:Enter two integers:Enter two integers: and on and on.. you get the idea.