#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <functional>
#include <set>

using namespace std;

int main()
{	
	int n;
	cin>>n;

	unsigned long long res=0;
	if(n==3) res=7;
	else{
		while(n>=2){res*=10;res+=1; n-=2;}
	}

	cout<<res<<endl;

	return 0;

}