5387

#include <bits/stdc++.h>

using namespace std;

int main() {
    freopen("input.txt", "r", stdin);

    string s;
    cin >> s;
    int k = 0, mx = 0;
    for (int i = 0; i < s.size() - 1; ) {
        if (s[i] >= 'A' && s[i] <= 'C' && s[i + 1] >= '1' && s[i + 1] <= '3') {
            k++;
            i += 2;
            continue;
        } else {
            mx = max(k, mx);
            k = 0;
        }
        i++;
    }
    cout << mx;

    return 0;
}