codechef PRIMEGAME

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long int
#define ld long double
#define pb push_back
#define p_b pop_back
#define si stack<int>
#define sll stack<ll>
#define sc stack<char>
#define vi vector<int>
#define vll vector<ll>
#define mii map<int, int>
#define msi map<string, int>
#define mci map<char, int>
#define qc queue<char>
#define qi queue<int>
#define qll queue<ll>
using namespace std;

bool isp(long n){
    for(int i = 2; i*i <= n; i++){
        if(n%i == 0){
            return false;
        }
    }

    return true;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int p[1000001];
    p[0] = 0;
    p[1] = 0;
    int count = 0;
    for(int i = 2; i < 1000001; i++){
        if(isp(i)){
            count++;
        }

        p[i] = count;
    }

    long t;
    cin >> t;
    while(t--){
        long n, k;
        cin >> n >> k;
        if(p[n] > k){
            cout << "Divyam\n";
        } else{
            cout << "Chef\n";
        }
    }
    return 0;
}