第二期训练白银组第一题

Sum Problem

Time limit 2000 ms
Memory limit 262144 kB

Problem Description

Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not.
Unfortunately, not all numbers are lucky. Petya calls a number nearly lucky if the number of lucky digits in it is a lucky number. He wonders whether number n is a nearly lucky number.

Input

The only line contains an integer n (1 ≤ n ≤ 1018).
Please do not use the %lld specificator to read or write 64-bit numbers in С++. It is preferred to use the cin, cout streams or the %I64d specificator.

Output

Print on the single line “YES” if n is a nearly lucky number. Otherwise, print “NO” (without the quotes).

Examples

Input

40047

Output

NO

Input

7747774

Output

YES

Input

1000000000000000000

Output

NO

Note

In the first sample there are 3 lucky digits (first one and last two), so the answer is “NO”.
In the second sample there are 7 lucky digits, 7 is lucky number, so the answer is “YES”.
In the third sample there are no lucky digits, so the answer is “NO”.

扫描二维码关注公众号，回复： 5014985 查看本文章

问题链接：CodeForces - 110A

问题简述：

输入一个整型数字，计算整数的“4”和“7”，若两者个数和为4或7则输出YES，否则则输出NO。

问题分析：

定义一个整形，然后利用循环提取出每个数位的数判断是否为“4”或“7”并记录，最后根据记录的“4”和“7”的个数判断是否输出YES

程序说明：

利用long long定义一个可以容纳10¹⁸的数，通过while循环来得到每一个数位的数并进行判断记录，最后通过sum来判断是否输出YES
　　
AC通过的C语言程序如下：

#include <iostream>
using namespace std;
int main()
{
	long long n;
	cin >> n;
	long long temp;
	temp = n;
	int i = 0;
	int middle;
	int sum = 0;
	while (temp)
	{
		
		middle = temp % 10;
		if(middle==4||middle==7)
		{
			sum++;	
		}
		temp /= 10;
	}
	if (sum == 7 || sum == 4)
	{
		cout << "YES" << endl;
	}
	else cout << "NO" << endl;
}