Input numbers. Calculate Sum and Average (Mean) with using do-while loop

#include<stdio.h>
main()
{
    int i=0,n,sum=0;
    float avg=0.0; 
    do
    {
       printf("Enter Numbers. (-999 Exit) : "); 
       scanf("%d",&n);
       if(n == -999)      
            break;  
       sum+=n;
       ++i;
    }while(1);  
    avg=sum/(float)i;
    printf("Sum=%d\nAvg=%f",sum,avg);
}

Output