#include <iostream>
#include <string>

int main() {
    std::string s;
    int max;
    int a=0;
    while(std::getline(std::cin,s)) {
        for (auto&c:s) {
            if (c=='x') {
                max=(a>max)?a:max;
                a=0;
            }
            else if (c=='o') {
                a++;
            }
        }
    }
    std::cout<<max<<std::endl;
    
}