#include <stdio.h>

int main() {
    int a;
    scanf("%d", &a);
    
    if (a == 1 ){
        printf("dog");    
    } else if (a == 2){
        printf("cat");
    }else if (a == 3){printf("chick");
    }else {printf(" i don't know.");}
    
    return 0;
}