#include<iostream>
#include<stdio.h>

using namespace std;

int main()
{
	int N;
	int multiplier=1;
	int one=0, seven=0;
	cin >> N;
	if (N % 2 && N>=3)
	{
		seven++;
		N -= 3;
	}
	one = N / 2;
	N = 0;
	while (one)
	{
		N += multiplier;
		one--;
		multiplier *= 10;
	}
	if(seven)
		N += multiplier * 7;
	cout << N;

	return 0;
}