#include<iostream>
using namespace std;
const string T="yukicoder";
string S;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin>>S;
	int ans=0;
	for(int i=0;i<S.size();)
	{
		if(S[i]!=T[0])
		{
			i++;
			continue;
		}
		int j=i+1;
		while(j<S.size()&&S[j]==T[(j-i)%9])j++;
		ans=max(ans,j-i);
		i=j;
	}
	cout<<ans/9<<endl;
}