#include <stdio.h>
#include <stdlib.h>

//8=============>

int is_prime(int number){ // returns one if prime
	if((number % 2 ) == 0 && number != 2){
		return 0;
	}
	if(number == 2){
		return 1; // two is a special case
	}
	
	int c = 2;
	while (c != number){
		if((number % c) == 0 && c != number){
			return 0;
		}
		++c;
	}
	return 1; 
}
int main(void){
	int a = 0,
 	d = 0;
	printf("Find all odd factors of: ");
	scanf("%d", &a); if (a == 0) return 0;
	printf("\n");
	
	int b = 2;
	while(b != a){
		printf("%d / %d...", b, a);
		if((a % b) == 0 && is_prime(b) && b > d){
			d = b; printf(" prime factor found!");
		}
		printf("\n");
		++b; 
	}
	printf("Largest prime factor of %d: %d (by %d)\n",a, d, a / d);
	return 0;
}