C programme to print twin prime numbers between limits

#include <stdio.h>
#include <conio.h>
 main()
{
int i,j,ip=1,count,n1,n2;
printf("enter limits");
scanf("%d%d",&n1,&n2);
for(i=n1;i<=n2;i++)
{
count=0;
for(j=1;j<=i;j++)
if((i%j)==0)
count++;
if(count==2)
{
if((i-ip)==2)
printf("%d%d",ip,i);
ip=i;
}
}