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Module DEMO-32-59DEMO-C-32

Count Digit Seven using for

DEMO-C-32 • Programming in C

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Problem Statement

Write a program that counts how many times the digit 7 appears in a given non-negative integer.

For example, in the number 752717, the digit 7 appears 3 times (at positions 1, 4, and 6 from the right, 0-indexed).

Your program should read one integer from standard input and output the count of digit 7 occurrences.

Constraints

0 ≤ N ≤ 10^18 The input will fit in a 64-bit signed integer type

Input Format

A single line containing a non-negative integer N (0 ≤ N ≤ 10^18).

Output Format

A single integer representing the number of times digit 7 appears in N.

Sample Testcases

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Sample #1
Public sample
Input
752717
Output
3
Explanation
Sample case: 7 appears at positions 0, 3, and 5 (from right to left, 0-indexed)
Sample #2
Public sample
Input
123456
Output
0
Explanation
No occurrence of digit 7
Sample #3
Public sample
Input
0
Output
0
Explanation
Zero contains no 7s
Sample #4
Public sample
Input
987654321
Output
1
Explanation
Only one occurrence of digit 7
Sample #5
Public sample
Input
7
Output
1
Explanation
Single digit 7
Sample #6
Public sample
Input
7799
Output
2
Explanation
Large number with 7s at the beginning

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