Nearly Lucky String

Given a string s, determine if it is a nearly lucky string. A string is defined as nearly lucky if the number of lucky digits it contains is between 1 and 3, inclusive. Lucky digits are defined as 4 or 7. Mathematically, if we denote the count of lucky digits by \(\text{lucky\_count}\), then the string is nearly lucky if and only if \(1 \leq \text{lucky\_count} \leq 3\).

Your task is to implement a function that reads a string from standard input and prints True to standard output if the string is nearly lucky, and False otherwise.

inputFormat

The input consists of a single line containing a non-empty string s which may include digits, letters, and other characters.

Input Format:

A single line representing the string s

outputFormat

Output a single line: True if the string is nearly lucky, and False otherwise.

Output Format:

True or False

447

True