Untitled

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ull unsigned long long
#define FOR(i,a,b) for (int i=a;i<=b;i++)
#define FOR_ll(i,a,b) for (ll i=a;i<=b;i++)
#define REP(i,a,b) for (int i=a;i>=b;i--)
#define MAX(a,b,c) max(a,max(b,c))
#define MIN(a,b,c) min(a,min(b,c))
#define ii pair<int,int>
#define F first
#define S second
#define PB push_back

int main()
{
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int n;
    cin>>n;
    int k=1, d=1;
    while (1)
    {
        k*=2;
        if (n-k>=0) n-=k;
        else break;
        d++;
    }

    if (n==0)
    {
        FOR(i,1,d-1) cout<<'7';
    }
    else
    {
        n--;
        bitset<20> a;
        a=n;
        REP(i,d-1,0)
        if (a[i]==0) cout<<4;
        else cout<<7;
    }

    return 0;
}