#include <cstdio>
#include <algorithm>
#define ll long long
using namespace std;
ll num[10000000];
int T;
ll n;
int cnt;
void dfs(int len,ll number,int x,int y)
{
    if (len > 18)
        return;
    if (x + 1 == y) num[++cnt] = number * 10 + 4;dfs(len + 1,number * 10 + 4,x + 1,y);
    if (x == y + 1) num[++cnt] = number * 10 + 7;dfs(len + 1,number * 10 + 7,x,y + 1);
}
int main()
{
    scanf("%d",&T);
    dfs(1,0,0,0);sort(num + 1,num + 1 + cnt);
    while (T--)
    {
        scanf("%I64d",&n);
        int ans = lower_bound(num + 1,num + 1 + cnt,n) - num;
        if (n > num[cnt])
        {
            for (int i = 1;i <= 10;i++) printf("4");
            for (int i = 1;i <= 10;i++) printf("7");
printf("\n");
        }
        else
        printf("%I64d\n",num[ans]);
    }
}