随机生成20以内加减法,5次答题并统计正确和错误题数

import random
right = 0
wrong = 0
print('答题系统,5道题,现在开始!')
count = 1
while count < 6:
    a = random.randint(1,20)
    b = random.randint(1,20)
    s = '+-'
    fh = random.choice(s)
    if a < b and fh =='-':
        result = int(input('%d %s %d =' % (b, fh, a)))
        if result == b-a:
            print('答对了')
            right += 1
        else:
            print('答错了,答案是:',(b-a))
            wrong += 1
    elif a > b and fh == '-':
        result = int(input('%d %s %d =' % (a, fh, b)))
        if result == a-b:
            print('答对了')
            right += 1
        else:
            print('答错了,答案是:',(a-b))
            wrong += 1
    else:
        result = int(input('%d %s %d =' % (a, fh, b)))
        if result == a+b:
            print('答对了')
            right += 1
        else:
            print('答错了,答案是:', (a - b))
            wrong += 1
    count += 1
print('答题结束,正确%d道,错误%d道' % (right,wrong))