Problem:
Score : 200 points

Problem Statement

Snuke is interested in strings that satisfy the following conditions:

The length of the string is at least N.

The first N characters equal to the string s.

The last N characters equal to the string t.

Find the length of the shortest string that satisfies the conditions.

Constraints

1≤N≤100

The lengths of s and t are both N.

s and t consist of lowercase English letters.

Input

The input is given from Standard Input in the following format:

N
s
t

Output

Print the length of the shortest string that satisfies the conditions.

Sample Input 1

3
abc
cde

Sample Output 1

5

The shortest string is abcde.

Sample Input 2

1
a
z

Sample Output 2

2

The shortest string is az.

Sample Input 3

4
expr
expr

Sample Output 3

4

The shortest string is expr.

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
int main() {

	int n, x, i;
	
	std::cin >> n;
	std::cin >> x;

	
	if (n == 1) {
		if (x == 1) {
			std::cout << "Yes\n";
			std::cout << 1;
		}
		else {
			std::cout << "No";
		}
	}
	else if (n == 2) {
		if (x == 2) {
			std::cout << "Yes\n";
			std::cout << 1; std::cout << "\n"; std::cout << 2; std::cout << "\n"; std::cout << 3;
		}
		else {
			std::cout << "No";
		}
	}
	else {
		if (x == 1) {
			std::cout << "No";
		}
		else if (x == 2 * n - 1) {
			std::cout << "No";
		}
		else if (x == 2) {
			std::cout << "Yes\n";
			for (i = 1; i <= 2 * n - 1; i++) {
				if (i < n - 1) {
					std::cout << i + 4;
				}
				else if (i < n + 2) {
					std::cout << n + 2 - i;
				}
				else if (i == n + 2) {
					std::cout << 4;
				}
				else {
					std::cout << i;
				}
			}
			std::cout << "\n";
		}
		else {
			std::cout << "Yes\n";
			for (i = 1; i <= 2 * n - 1; i++) {
				if (i == n - 1) {
					std::cout << x - 1;
				}
				else if (i == n) {
					std::cout << x;
				}
				else if (i == n + 1) {
					std::cout << x + 1;
				}
				else if (i == n + 2) {
					std::cout << x - 2;
				}
				else if (i == x - 1) {
					std::cout << n - 1;
				}
				else if (i == x) {
					std::cout << n;
				}
				else if (i == x + 1) {
					std::cout << n + 1;
				}
				else if (i == x - 2) {
					std::cout << n + 2;
				}
				else {
					std::cout << i;
				}
				std::cout << "\n";
			}
		}
	}
	return 0;


}