#include <stdio.h>

int statistic(int x, int y)//统计个数函数
{
    int i = 0;//遍历
    int k = 0;//计数用
    for (i = x; i <= y; i++)
    {
        int sum = 0;//统计位数和
        int d = i;
        while (d != 0)//循环条件
        {
            int e = d % 10;
            d = d / 10;
            sum = sum + e;
            
        }
        if (sum % 5 == 0)//计数条件
            {
                k++;
            }
    }
    return k;
}

int main() {
    int a, b;//范围
    scanf("%d %d", &a, &b);
    int c = statistic(a, b);
    printf("%d\n", c);//打印输出
    return 0;
}