ХЭШ C

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int,int>
#define vec vector
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n";
}

void cvl(vector <ll> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n";
}


void cvv(vector <vector <int> > &v){
    for (auto x: v) cv(x);
    cout<<"\n";
}

void cvb(vector <bool> v){
    for (bool x: v) cout<<x<<' ';
    cout<<"\n";
}

void cvs(vector <string>  v){
    for (auto a: v){
        cout<<a<<"\n";
    }
}

void cvp(vector <pii> a){
    for (auto p: a){
        cout<<p.first<<' '<<p.second<<"\n";
    }
    cout<<"\n";
}

ll mod = 1e9+7, p = 101;

bool sh=0;

ll f(char x){
    ll d ;
    d = x - 'A' + 1;
    return d;
}
/*
zabcd
abcdz
*/
int main()
{
    /*ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);*/
    string s; cin>>s;
    int n = s.size();
    vector <ll> powp(2*n, 1);
    for (int i = 1; i < 2*n; ++i){
        powp[i] = powp[i-1] * p % mod;
    }
    vector <ll> pf(n);
    pf[0] = f(s[0]);
    for (int i = 1; i < n; ++i){
        pf[i] = pf[i - 1] + powp[i] * f(s[i]);
        pf[i] %= mod;
    }

    vector <int> div;
    for (int i = 1; i <= n; ++i){
        if (n % i == 0){
            div.push_back(i);
        }
    }
    reverse(div.begin(), div.end());
    //0 3 6 9 12
    //0 2 4
    for (int d: div){
        bool ok = 1;
        for (int i = 1; i < n / d; ++i){
            int a = i * d, b = i * d + d - 1;
            if ((pf[b] - pf[a-1] + mod) % mod != pf[d - 1] * powp[a] % mod){
                ok=0;
                break;
            }
        }
        if (ok){
            cout<<d;
            exit(0);
        }
    }
}