#include <stdio.h>
#include <stdlib.h>
#include <cstring>

struct book
{
	char name[30];
	char field[30];
	int year;
};





int main() {
	book libry[3];
	int i, k;
	for (i = 0; i < 3; i++)
	{
		printf("Enter name of %d book:", i + 1);
		gets_s(libry[i].name);
		printf("Enter field of %d book:", i + 1);
		gets_s(libry[i].field);
		printf("Enter year of %d book:", i + 1);
		scanf("%d", &libry[i].year);
		getchar();
	}
	for (i = 0; i < 3; i++)
	{
		printf("\n %d. %s", i + 1, libry[i].name);
		printf(", %s , %d", libry[i].field, libry[i].year);
	}

	k = 0;
	for (int i = 0; i < 3; i++)
		if (strcmp(libry[i].field, "Physics") == 0)
			k = k + 1;
	printf("\n Sum of Physics books: %d", k);


	int oldest_number = 0;
	for (int i = 1; i < 3; i++) {
		if (libry[oldest_number].year > libry[i].year){
			oldest_number = i;
		}
	}
	printf("\n Oldest is: %s with year %d", libry[oldest_number].name, libry[oldest_number].year);



	getchar();
	return 0;
}