#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#define N 10010

int a[N], b[N], c[N]; //用来存放每个礼炮车的发射时间 
int num[N]; 		  //存放没有重复的声响时间
int count = 0; 		  //记录观众可以听到的声响

bool isRepeat(int a)
{
	for(int i = 0; i < count; i++)
		if(a == num[i]) return true;
	return false;
} 
int main()
{
	int i;
	a[1] = b[1] = c[1] = 1; 
	for(i = 2; i <= 21; i++)
	{
		a[i] = a[i - 1] + 5;
		b[i] = b[i - 1] + 6;
		c[i] = c[i - 1] + 7;
	}
	
	for(i = 1; i <= 21; i++)
	{
		if(!isRepeat(a[i])) num[count++] = a[i];
		if(!isRepeat(b[i])) num[count++] = b[i];
		if(!isRepeat(c[i])) num[count++] = c[i];
	}
	printf("%d\n", count);
	return 0;
 }