#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>

typedef struct {
	double X;
	double Y;
	double Z;
}koord;

int main()
{
	int db = 0;
	koord akt;
	koord* tomb, * tmp;

	while (scanf_s("%lf,%lf,%lf", &akt.X, &akt.Y, &akt.Z) == 0)
	{
		db++;
		//Nyujtozkodo dinamikus tomb
		tmp = (koord*)malloc(sizeof(koord) * db);
		for (int i = 0; i < db; ++i)
		{
			tmp[i] = tomb[i];
		}
		free(tomb);
		tomb = tmp;
		//Idaig
		//Berakom a most beolvasott értéket
		tomb[db - 1] = akt;
	}
	//Itt már lesz egy coord nevű tömböd, aminek count db eleme van
	double max = tomb[1].Z - tomb[0].Z;
	int indmax;
	for (int j = 1; j < db; j++) {
		if (tomb[j].Z - tomb[j - 1].Z > max) {
			tomb[j].Z - tomb[j - 1].Z == max;
			indmax = j - 1;
		}
	}
	return 0;
}