#include <iostream>
#include <algorithm>
#include <iterator>
#include <set>
#include <string>

using namespace std;

int main()
{
    typedef string::const_iterator iterator;
    string s;
    cin >> s;
    set<string> found;
    int min = INT_MAX;


    if (2 < s.size())
        for (iterator i = s.begin() + 1, j = s.end(); i != j; ++i)
            for (iterator x = s.begin(); x != i; ++x)
            {
                iterator tmp = mismatch(i, j, x).second;;
                if (tmp - x > 1)
                {
                    found.insert(string(x, tmp));
                    if(string(x, tmp).length() < min)
                    {
                        min = string(x, tmp).length();
                    }
                }

            }
    if(min == INT_MAX)
    {
        min = 1;
    }
    cout << min << endl;
    return 0;
}