#include<stdio.h>
#include<stdlib.h>
void main()
{
	int thang;
	printf("nhapthang: ");
	scanf_s("%d", &thang);
	if (thang == 1 || thang == 5 || thang == 7 || thang == 7 || thang == 8 || thang == 10 || thang == 12)
		printf("thang %d co 31 ngay",thang);
	else if (thang == 2)
		printf("thang %d co 28 ngay",thang);
	else
		printf("thang %d co 30 ngay",thang);
	system("pause");
}