#include <stdio.h>

int main() {

	// declaring and defining the 14 digit numbers
	int digits[] = {3, 4, 2, 1, 5, 6, 8, 3, 1, 5, 1, 5, 6, 5};

	// declaring the variable for the total of the first, third, fifth elements and so on...
	int sum_odd;

	printf("=====================================\n");
	printf("First set of digits\n");
	printf("=====================================\n");
	// loop through the first, third, fifth element and so on
	for(size_t i = 0; i < (sizeof(digits) / sizeof(digits[0])); i += 2) {
		// multiplying the value of each element by 2
		digits[i] = digits[i] * 2; 
		printf("Element %d: %d\n", ((int)i + 1), digits[i]);	

		// adding the value of the current element to the old sum_even value
		sum_odd += digits[i];
	}

	// declaring the variable for second, forth, sixth elements and so on...
	int sum_even;

	printf("\n");
	printf("=====================================\n");
	printf("Second set of digits\n");
	printf("=====================================\n");
	// loop through the second, forth, sixth digits and so on
	for(size_t j = 1; j < (sizeof(digits) / sizeof(digits[0])); j += 2) {
		// multiplying the value of each element by 2
		digits[j] = digits[j] * 2; 
		printf("Element %d: %d\n", ((int)j + 1), digits[j]);	

		// adding the value of the current element to the old sum_even value
		sum_even += digits[j];
	}

	// add the sum of sum_odd and sum_even together
	int total = sum_odd + sum_even;
	// print out the value
	printf("\n");
	printf("=====================================\n");
	printf("Total: %d\n", total);
	printf("=====================================\n");
	
	return 0;
}