#include <bits/stdc++.h>

#define pout(n)  printf ("%d\n", n)

#define rep(i,a,n) for (int i = a;i < n;i++)
#define per(i,n,a) for (int i = n-1;i >= a;i--)

const int d4x[4] = {1, 0, -1, 0};
const int d4y[4] = {0, 1, 0, -1};
const int d8x[8] = { 1,1,0,-1,-1,-1,0,1 };
const int d8y[8] = { 0,1,1,1,0,-1,-1,-1 };

#define MAX_N (int)2e5+20
#define INF 1e12+20

typedef long long ll;
using namespace std;

ll n,ans = 1;
int main() {
    cin >> n;
    if(n == 3){
        pout(7);
    }
    else if(n/2 != 0 && n%2 == 1){
        n /= 2;
        rep(i,1,n){
            ans *= 10;
            ans++;
            if(i == n-1){
                ans = ans-1+7;
            }
        }
        printf("%lld\n",ans);
    }
    else if(n/2 != 0 && n%2 == 0){
        n /= 2;
        rep(i,1,n){
            ans *= 10;
            ans++;
        }
        printf("%lld\n",ans);
    }
    else pout(0);
    return 0;
}