#include<stdio.h>
#include<conio.h>

main()
{
    int n,i,sum=0;
    printf("Input: ");
    scanf("%d",&n);

    for(i=1;i<=n;++i){

        printf("%d ",i);
        sum+=i;
    }

    printf("\nThe sum of natural numbers is: %d",sum);

 getch();
}