Hamming Distance

Time limit2sMemory limit1024 MB

Summary

Given two equal-length strings, count the positions where their characters differ.

Level: Easy1 of 10
Topics: String, Implementation
Solved: No attempts yet

Problem

You are given an integer N and two strings S and T, each of length N. Print the Hamming distance between S and T.

The Hamming distance between S and T is the number of indices i (1 ≦ i ≦ N) where the i-th character of S differs from the i-th character of T.

Input

The input is given in the following format.

N
S
T

Output

Print the Hamming distance between S and T.

Print only the result. Do not print anything else, such as a prompt for input.

Constraints

1 ≦ N ≦ 100.
N is an integer.
S and T are strings of length N consisting of lowercase English letters.

Examples3

Example 1
Input
```
3
joi
ioi
```
Expected output
```
1
```
Example 2
Input
```
5
march
april
```
Expected output
```
4
```
Example 3
Input
```
6
sample
sample
```
Expected output
```
0
```