#include <iostream>

int gcd(int a, int b) {
	return b ? gcd(b, a % b) : a;
}

void findGcd(int* couples, int numCouples) {
	for (int i = 0; i < numCouples; i++) {
		printf("GCD of the %d%s%d%s", (i + 1), " couple: ", gcd(couples[2 * i], couples[2 * i + 1]), ".\n");
	}
}

int getNumber(int minValue, int maxValue) {
	int number;
	bool isCorrect;
	do {
		isCorrect = true;
		printf("\nEnter: ");
		scanf_s("%d", &number);
		if (number > maxValue || number < minValue) {
			printf("Your value will be more than %d%s%d%s", minValue, " and less than ", maxValue, ". Try again.");
			isCorrect = false;
		}
	} while (!isCorrect);
	return number;
}


void getCouples(int* couples, int numCouples) {
	for (int i = 0; i < numCouples; i++) {
		printf("Enter %d %s", (i + 1), "couple.");
		printf("\nEnter the first number of this couple.");
		couples[2 * i] = getNumber(1, INT_MAX);
		printf("Enter the second number of this couple.");
		couples[2 * i + 1] = getNumber(1, INT_MAX);
	}
}

int main() {
    int couples[50];
	printf("Enter the number of couples.");
	int numCouples = getNumber(1, 25);
	printf("Now enter couples.");
	getCouples(couples, numCouples);
	findGcd(couples, numCouples);
}