#include<stdio.h>

int main(void) {
	long int one = 1;
	long int num = 0;
	int N;
	scanf("%d", &N);
	while (N > 3) {
		num += one;
		one *= 10;
		N -= 2;
	}
	if (N == 2) {
		num += one;
	}else {
		num += (one * 7);
	}
	printf("%ld", num);
}