题解 | #完全数计算#

if __name__ == "__main__":
    while True:
        try:
            n = int(input().strip())
            counter = 0
            for i in range(1,n+1):
                pf = 0
                j = 1
                while True:
                    if i%j == 0:
                        divisor = i/j  # 记录较大的约数divisor
                        # 若divisor<=约数j，则表示i已经没有其他约数，减少不必要循环
                        if divisor <= j: 
                            break
                        pf += j + divisor
                    j += 1
                if pf == 2*i:  # 因为循环中当约数为1时，把i本身也加进pf里，所以pf = 2*i。
                    counter += 1
            print(counter)
        except:
            break