codefroces 110A Nearly Lucky Number（模拟水题）

A. Nearly Lucky Number
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time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits4 and 7. For example, numbers47, 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 numbern 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).

Sample test(s)

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".

检测是不是nearly lucky number（一个数中含有4和7的总个数是个lucky number，则这个数是nearly lucky number），如果是，输出YES，否则是NO；

代码:

#include <iostream>#include<memory.h>#include<stdlib.h>using namespace std;int check(long long int count1){    int k;    long long int c=1;    if(count1==0)        return 0;    while(count1)    {        k=count1%10;        if(!(k==4||k==7))        {            return 0;        }        c=c*10;        count1/=c;    }    return 1;}int main(){    char c[101];    int k,s,i,j;    long long count1;    while(cin>>c)    {        count1=0;        k=strlen(c);        for(i=0; i<k; i++)        {            if(c[i]=='4'||c[i]=='7')                count1++;        }        if(check(count1))            cout<<"YES"<<endl;        else            cout<<"NO"<<endl;        memset(c,'\0',sizeof(c));    }    return 0;}