/* -*- coding: utf-8 -*-
 *
 * 2298.cc:  No.2298 yukicounter - yukicoder
 */

#include<cstdio>
#include<cstring>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 1000000;
const int L = 9;
const char t[] = "yukicoder";

/* typedef */

/* global variables */

char s[MAX_N + 4];
int dp[MAX_N + 1];

/* subroutines */

/* main */

int main() {
  scanf("%s", s);
  int n = strlen(s);

  int maxc = 0;
  for (int i = 0; i < n; i++) {
    if (s[i] == t[dp[i] % L]) {
      dp[i + 1] = dp[i] + 1;
      maxc = max(maxc, dp[i + 1] / L);
    }
  }

  printf("%d\n", maxc);
  return 0;
}