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)

///Bismillahir Rahmanir Rahim
#include<bits/stdc++.h>

#define                           int                         long long
#define                           fi                          first
#define                           si                          second
#define                           mp                          make_pair
#define                           pb                          push_back
#define                           pi                          pair<int,int>
#define                           f(i,l,r)                    for(int i=l;i<=r;i++)
#define                           rf(i,r,l)                   for(int i=r;i>=l;i--)
#define                           done(i)                     cout<<"done = "<<i<<endl;
#define                           fast                        ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);




using namespace std;

const int inf=1e18;
const int mod=1e9+7;
const int M=100009;

inline int bigmod(int B,int P){int R=1;while(P>0){if(P&1){R=(R*B)%mod;}P>>=1;B=(B*B)%mod;}return R;}
inline int ad(int x,int y){int ret=(x%mod+y%mod)%mod;if(ret<0){ret+=mod,ret=ret%mod;}return ret;}
inline int sub(int x,int y){int ret=((x%mod)-(y%mod)+mod)%mod;if(ret<0){ret+=mod,ret=ret%mod;}return ret;}
inline int gun(int x,int y){int ret=((x%mod)*(y%mod))%mod;if(ret<0){ret+=mod,ret=ret%mod;}return ret;}


 main()

{
    fast
    int n;
    cin>>n;
    string s,t;
    cin>>s>>t;
    int cnt=0,ses=0;
    f(i,0,n-1)
    {
       string suf=s.substr(i);
       int len=suf.size();
       string pre=t.substr(0,len);
       if(suf==pre)
       {
           ses=2*i+len;
           cout<<ses<<endl;
           return 0;
       }
    }
    ses=2*n;
    cout<<ses<<endl;
    return 0;

}