#include <bits/stdc++.h>
#define for1(s,n) for(int i = s; i < n; i++)
#define for1j(s,n) for(int j = s; j < n; j++)
using namespace std;
string s;
int d[1100], ans;
int main() {
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> s;
int n = s.length();
for1(0, n) d[i] = 1;
for1(1, n) {
for1j(0, i) {
if((i - j) % 2 && s[i] == s[j]) {
d[i] = max(d[i], d[j] + 1);
}
}
}
for1(0, n) {
ans = max(d[i], ans);
}
cout << ans;
}