#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

int main() {

    ios::sync_with_stdio(false);
    cin.tie(0);

    vector<int> vec;
    char prev = 'a'; //インプットがx,oだけなので
    char  curr = 'a'; //それ以外の適当な文字aで初期化
    int count = 1;
    for (int i = 0; i < 14; ++i) {
        cin >> curr;
        if (prev == 'a') { //最初だけ
            prev = curr;
            continue;
        }
        if (prev != curr) {
            if (prev == 'o') {
                vec.push_back(count);
            }
            count = 1;
        } else {
            count++;
        }
        prev = curr;
    }
    vec.push_back(count);

    cout << *max_element(vec.begin(), vec.end()) << endl;
    return 0;
}