Dynamic memory allocation in C

//dynamic memory allocation
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
int main()
	{
		int s, i,*p,*ptr,*q,sum=0;
		printf("enter the count for numbers to input\n");
		scanf("%d",&s);
		ptr=(int*)malloc(sizeof(int)*s);
		p=ptr;
		printf("memory allocated %u\n",ptr);
		if(ptr==NULL)
		{
			printf("out of memory\n\n");
			exit(0);
		}
		printf("enter %d elements\n",s);
		for(i=1;i<=s;i++)
		{
			scanf("%d",ptr);
			sum=sum+*ptr;
			ptr++;
		}
		printf("............displaying elements........\n");
		for(i=1;1<=s;i++)
		{
			printf("%d\n",*p);
			p++;
		}
		printf("addition is =%d\n",sum);
		printf("enter the new count for the number to input\n");
		scanf("%d",&s);
		ptr=(int*)realloc(ptr,s*sizeof(int));
		q=ptr;
		if(ptr==NULL)
		{
			printf("out of memory\n");
			exit(0);
		}
		printf("reallocated memory is: %u\n",ptr);
		printf("enter %d elements\n",s);
		for(i=1;i<=s;i++)
		{
			scanf("%d",ptr);
			sum=sum+*ptr;
			ptr++;
		}
		printf("..............displaying the elements..........\n");
		for(i=1;i<=5;i++)
		{
			printf("%d\n",*q);
			q++;
		}
		printf("addition is:  %d\n",sum);
		getch();
		return 0;
	}