Nearly Lucky Number

Source: Codeforces

Version: Phuoc Hung OJ Extended

Problem Statement

A lucky digit is 4 or 7. Count how many lucky digits occur in positive n. Print YES if this count is a positive integer consisting only of lucky digits; otherwise print NO. Since n has at most 19 digits, this is equivalent to count 4 or 7.

Input

One positive integer n.

Output

Print exactly YES or NO.

Subtasks

• Subtask 1 (20%): $1\le n\le999$.
• Subtask 2 (30%): $1\le n\le10^9$.
• Subtask 3 (50%): $1\le n\le10^{18}$.

Examples

Example 1

Input

40047

Output

NO

Explanation

There are three lucky digits; 3 is not lucky.

Example 2

Input

7747774

Output

YES

Explanation

All seven digits are lucky, and count 7 is itself lucky.