print((sum(si != ti for si, ti in zip(eval(input()), eval(input())))))

print((sum(a!=b for a,b in zip(*open(0)))))
print((sum(si != ti for si, ti in zip(eval(input()), eval(input())))))

print((sum(a != b for a, b in zip(*open(0)))))

-print((sum(si != ti for si, ti in zip(eval(input()), eval(input()))))) +print((sum(a != b for a, b in zip(*open(0)))))