#include<stdio.h> 

int main()
{
 
int sum=0,n,i=0;
printf("Enter n\n");
scanf("%d",&n);
 
for(i=1; i<=n; i++)
{
sum=sum+i;
}
 
 
printf("Sum of %d natural numbers is %d",n,sum);
 
return 0;
}
     
           
Note: Need to be arranged in compiler after copied
   

 OutPut:

Enter n 4 Sum of 4 natural numbers is 10