#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,l,r) for(int i=(l);i<(r);++i)

int main(){
	string s; cin>>s;
	regex ptn{R"((yukicoder)*)"};
	vector<string> v;
	sregex_iterator end, itr{s.begin(),s.end(),ptn};
	for(; itr!=end; ++itr) v.push_back(itr->str());
	sort(v.rbegin(),v.rend());
	int k=v[0].size();
	cout<<k/9<<endl;
}