#include <stdio.h>
#include <algorithm>
#include <iostream>
using namespace std;

long long a[2000000];

int main() {
    ///freopen("1001.in", "r", stdin);
    int cnt = 0;
    for(int i = 1; i <= 18; i ++) {
        for(int j = 0; j < (1<<i); j ++) {
            long long cur = 0;
            int gas1 = 0, gas2 = 0;
            for(int k = 0; k < i; k ++) {
                cur = 1ll * cur * 10;
                if(j & (1<<k)) cur += 4, gas1 ++;
                else cur += 7, gas2 ++;
            }
            if(gas1 == gas2) a[cnt ++] = cur;
        }
    }
    sort(a, a + cnt);
    int n;
    scanf("%d", &n);
    for(int i = 1; i <= n; i ++) {
        long long x;
        scanf("%I64d", &x);
        int y = lower_bound(a, a + cnt, x) - a;
        if(y == cnt) puts("44444444447777777777");
        else printf("%I64d\n", a[y]);
    }
}