Description

Given several four-digit numbers, determine the count of numbers that satisfy the following condition: the result of subtracting the thousands digit, the hundreds digit, and the tens digit from the units digit is greater than zero.

Input Format

The input consists of two lines. The first line contains the integer n, representing the number of four-digit numbers. The second line contains n four-digit numbers. (n ≤ 100)

Output Format

The output is a single line containing an integer, representing the count of four-digit numbers that meet the specified condition.

5
1234 1349 6119 2123 5017

3