#include<bits/stdc++.h>
#define rep(i,a,n) for (int i = a;i < n;i++)
#define per(i,n,a) for (int i = n-1;i >= a;i--)
using namespace std;

int main() {
    int cnt = 0,tmp = 0;
    string s;
    rep(i,0,14) cin >> s[i];

    rep(i,0,14){
        if(s[i] == 'o'){
            tmp = max(++cnt,tmp);
        }else{
            if(s[i] == 'x') cnt = 0;
        }
    }
    cout << tmp << "\n";
}