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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <stdbool.h>
#include <limits.h>

#define lli long long int
#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)>(b)?(a):(b))
#define	abs(a) ((a)<0?-(a):(a))



int main(void){
	int n;
	char *s,*t;
	char *sh,*th;
	scanf("%d",&n);
	s = calloc(sizeof(char),n+1);
	t = calloc(sizeof(char),n+1);
	scanf("%s",s);scanf("%s",t);
	sh = s;th = t;
	while(*s){
		sh = s;
		th = t;
		while(*sh == *th){
			sh++;th++;
			if(!*sh){
				printf("%d\n", 2*n-(th-t));
				return 0;
			}
		}
		s++;
	}
	printf("%d\n", 2*n);
	return 0;
}