#include <stdio.h>

#include <conio.h>

void main()

{

int i, N, sum = 0;

clrscr();

printf(“Enter an integer number\n”);

scanf (“%d”, &N);

for (i=1; i <= N; i++)

{

sum = sum + i;

}

printf (“Sum of first %d natural numbers = %d\n”, N, sum);

}

/*—————————————-

Output

RUN1

Enter an integer number

10

Sum of first 10 natural numbers = 55

RUN2

Enter an integer number

50

Sum of first 50 natural numbers = 1275

——————————————*/