#include<bits/stdc++.h>
using namespace std;
const long long int mod = 1000000000000037;
const long long int base = 127;
long long int baza;
long long int n,n1,n2;
string s1,s2,s3;
vector<long long int>h1,h2;
///----------------------------------------------
void read()
{
    cin>>n;
    cin>>s1>>s2>>s3;
}
///----------------------------------------------
void assign_hash(long long int i, long long int s, vector<long long int>&h, long long int e)
{
    if(i==e)
    {
        h.push_back(s);
        return;
    }
    assign_hash(i+1,(s*base+s1[i])%mod,h,e);

    assign_hash(i+1,(s*base+s2[i])%mod,h,e);

    assign_hash(i+1,(s*base+s3[i])%mod,h,e);
}
///----------------------------------------------
void base_hash()
{
    baza=base;
    for(int i=1;i<n2;i++)
    {
        baza=(baza*base)%mod;
    }
    for(int i=0; i<(int)h1.size(); i++)
    {
        __int128 h,b;
        h=h1[i];
        b=baza;
        h=(h*b)%mod;
        h1[i]=h;
        //cout<<h1[]
    }
}
///----------------------------------------------
long long int binary_sear4(long long int k)
{
    long long int l=-1,r=h2.size(),ans=mod*2,m;
    while(l<=r)
    {
        //cout<<l<<" "<<r<<endl;
        m=(l+r)/2;
        if(k+h2[m]>=mod)
        {
            r=m-1;
            ans=h2[m];
        }
        else
        {
            l=m+1;
        }
    }
    return (ans+k)-mod;
}
///----------------------------------------------
void solve()
{
    n1=n/2;
    n2=n-n1;
    assign_hash(0,0,h1,n1);
    assign_hash(n1,0,h2,n);
    base_hash();
    sort(h2.begin(),h2.end());
    long long int sum1,sum2,min_sum=1e18+5;
    for(int i=0; i<(int)h1.size(); i++)
    {
        //cout<<h1[i]<<"  first hash "<<h2[0]<<endl;
        sum1=(h1[i]+h2[0])%mod;
        sum2=binary_sear4(h1[i]);

        //cout<<sum1<<" "<<sum2<<endl;
        min_sum=min(min_sum,min(sum1,sum2));
        //min_sum+=mod;
        //min_sum%=mod;
    }
    cout<<min_sum<<endl;
}
///----------------------------------------------
int main()
{
    read();
    solve();
    return 0;
}