#include <stdio.h>
#define key "yukicoder"

int linearSearch(char *p);

int main(void)
{
  char msg[10];

  scanf("%s", msg);
  printf("%c\n", key[linearSearch(msg)]);

  return 0;
}

int linearSearch(char *msg)
{
  for (int idx = 0; msg[idx] != '\0'; ++idx) {
    if (msg[idx] == '?') {
      return idx;
    }
  }
  return -1;
}