#include<iostream>
#include<string>
#include<queue>
#include<vector>
#include<cassert>
#include<random>
#include<set>
#include<map>
#include<cassert>
#include<unordered_map>
#include<bitset>
#include<numeric>
#include<algorithm>
using namespace std;
typedef long long ll;
const int inf=1<<30;
const ll INF=1LL<<62;
typedef pair<int,ll> P;
typedef pair<int,P> PP; 
const ll MOD=998244353;

int main(){
    string yukicoder="yukicoder";
    string S;
    cin>>S;
    int N=S.size();

    auto judge=[&](const string& s)->bool{
        if(s.size()<yukicoder.size()) return false;
        if(s==yukicoder) return true;
        return false;
    };

    vector<int> dp;
    int idx=0;
    for(int idx=0;idx<N;){
        if( judge(S.substr(idx,min(N-idx,(int)yukicoder.size()))) ){
            dp.push_back(1);
            idx+=yukicoder.size();
        }else{
            dp.push_back(0);
            idx++;
        }
    }

    int ans=0;
    int n=dp.size();
    vector<int> sum(n+1);
    for(int i=0;i<n;i++){
        if(dp[i]>0){
            sum[i+1]=sum[i]+dp[i];
        }
    }
    for(int i=0;i<=n;i++){
        ans=max(ans,sum[i]);
    }
    cout<<ans<<endl;

}