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: Accepted)

#include<bits/stdc++.h> 
using namespace std;
using ll=long long;
typedef pair<int,int> P;
#define fi first
#define se second
#define all(v) (v).begin(),v.end()
set<string> c;
const ll mod=1000000007;
const ll mod2=998244353;
const ll inf=100000000000000000;
ll gcd(ll a,ll b) {return b ? gcd(b,a%b):a;}
ll lcm(ll c,ll d){return c/gcd(c,d)*d;}
vector<int> dy={-1,0,1,0},dx={0,-1,0,1};
vector<vector<int>> graph;
map<char,ll> mp;
int main(){
int n;
cin>>n;
string s,t;
cin>>s>>t;
int cnt=0;
bool check=false;
while(1){
    if(cnt==n)break;
    check=true;
    int i=n-1;
    while(i-cnt>=0){
        if(s.at(i)!=t.at(i-cnt))check=false;
        i--;
    }
    if(check)break;
cnt++;
}
cout<<s.size()+cnt<<endl;
}