#include<cstdio>
#include<cmath>
using namespace std;
int main()
{
	int a,x,y,x2=0,y2=0,zong;
	double ju,shi=0;
	scanf("%d",&a);
	for(int i=1;i<=a;i++)
	{
		scanf("%d%d%d",&x,&y,&zong);
		ju=sqrt((x-x2)*(x-x2)+(y-y2)*(y-y2));
		shi+=ju/50*2+zong+zong*0.5; 
		//ceil上取整函数，int会有一些精度的损失 
		x2=x;
		y2=y;
	}
	printf("%.0lf",ceil(shi));
	return 0;
}