include <stdio.h>int add_digits(int);int main() { int n, result; printf("Enter a number\n"); scanf("%d", &n); result = add_digits(n); printf("%d\n", result); return 0;}int add_digits(int n) { static int sum = 0; if (n == 0) { return 0; } sum = n % 10 + add_digits(n / 10); return sum;
OUTPUT
Enter a number
342
9