Submission #3781127

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Source Code Expand

A, B = (int(i) for i in input().split())

def count49(N):
    if 0 <= N <= 3:
        return 0
    elif 4 <= N <= 8:
        return 1
    elif N == 9:
        return 2
    else:
        a = 2
        b = count49(N//10 - 1) * 8 + 2 * (N//10 - 1)
        if "4" in str(N//10) or "9" in str(N//10):
            c = N % 10 + 1
        else:
            c = count49(N % 10)
        return a + b + c

res = count49(B) - count49(A-1)
print(res)

Submission Info

Judge Result