#include<stdio.h> 

int main()
{

    int n,sum,num,i;

printf("Enter a Number:\n");
scanf("%d",&n);
printf("Enter %d positive integer numbers: \n",n);
sum=0;

for(i=1;i<=n;i++)
{
printf("Enter %d postive integer number\n",i);
scanf("%d",&num);

if(num<0)
{
 printf("Entered Negative no.\n");
i--; 
continue;
}
sum=sum+num;
}
 printf("Sum is %d",sum);

return 0;
}
     
           
Note: Need to be arranged in compiler after copied
   

 OutPut:

Enter a Number: 3 Enter 3 positive integer numbers: Enter 1 postive integer number 10 Enter 2 postive integer number 20 Enter 3 postive integer number 50 Sum is 80