cf1107d

#include<bits/stdc++.h>
using namespace std;
int n,mp[5500][5500];
int judge(int i){
    for(int j=1;j<=n;j++)
        if(mp[i][j]!=mp[i-1][j])return 0;
    return 1;
}
int main(){
    cin>>n;
    char ch;int a;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j+=4){
            cin>>ch;
            if(ch<=‘9‘&&ch>=‘0‘)a=ch-‘0‘;
            else a=10+ch-‘A‘;
            for(int k=3;k>=0;k--)
                mp[i][j+(3-k)]=(a>>k)&1;
        }
        
    int ans=0,tmp=1; 
    for(int i=2;i<=n;i++){
        if(judge(i))tmp++;
        else if(ans==0) ans=tmp,tmp=1;
        else ans=__gcd(ans,tmp),tmp=1;
    }
    
    for(int i=1;i<=n;i++)
        for(int j=i+1;j<=n;j++)
            swap(mp[i][j],mp[j][i]);
    tmp=1;
    for(int i=2;i<=n;i++){
        if(judge(i))tmp++;
        else ans=__gcd(ans,tmp),tmp=1;
    }
    printf("%d\n",__gcd(ans,tmp));
}