#include<stdio.h>
void ave_temper()
{
	float temper[31];
	float sum=0;
	int num,day=0;
	do
	{
		printf("enter temperature for day %d :",day);
		scanf("%f",temper+day);
	}
	while(*(temper+day++) > 0);

	num=day-1;
	for(day=0;day<num;day++)
	{
		sum+=*(temper+day);
	}

	printf("average is %4.1f \n",sum/num);

}