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#include <stdio.h>#define bool int#define true 1#define false 0bool is_prime ( int num ) {	int i = num - 1;	while ( i > 0 ) {		if ( i != 1 && num % i == 0 )			return false;		i--;	}	return true;}int main ( void ) {	int numbers[] = {13, 5678889, 7, 100003};	int i;	for ( i = 0; i < 4; i++ ) {		if ( is_prime ( numbers[i] ) )			printf ( "%d is a prime number.\n", numbers[i] );		else			printf ( "%d is not a prime number.\n", numbers[i] );	}	return 0;}