// Checks whether a user-specified value meets the UPC criteria 	
	
import java.util.*;	
	
public class UPC {	
	// main(): application entry point	
	public static void main(String[] args) {	
		final long MAX_POSSIBLE_UPC_CODE = 999999999999L;	
	
		// set input stream and get number	
		Scanner stdin = new Scanner(System.in);	
	
		System.out.print("Enter a 12-digit whole number: ");	
		long input = stdin.nextLong();	
		long number = input;	
	
		// determine whether number is a possible upc code	
		if ((input < 0) || (input > MAX_POSSIBLE_UPC_CODE)) {	
			// not a upc code	
			System.out.println(input + " is an invalid UPC code");	
		}	
		else {	
			// might be a upc code	
	
			// determine individual digits	
			int d12 = (int) (number % 10);	
			number /= 10;	
			int d11 = (int) (number % 10);	
			number /= 10;	
			int d10 = (int) (number % 10);	
			number /= 10;	
			int d9 = (int) (number % 10);	
			number /= 10;	
			int d8 = (int) (number % 10);	
			number /= 10;	
			int d7 = (int) (number % 10);	
			number /= 10;	
			int d6 = (int) (number % 10);	
			number /= 10;	
			int d5 = (int) (number % 10);	
			number /= 10;	
			int d4 = (int) (number % 10);	
			number /= 10;	
			int d3 = (int) (number % 10);	
			number /= 10;	
			int d2 = (int) (number % 10);	
			number /= 10;	
			int d1 = (int) (number % 10);	
			number /= 10;	
	
			// compute sums of first 5 even digits and the odd digits	
			int m = d2 + d4 + d6 + d8 + d10;	
			int n = d1 + d3 + d5 + d7 + d9 + d11;	
	
			// use UPC formula to determine required value for d12	
			int r = 10 - ((m + 3*n) % 10);	
	
			// based on r, can test whether number is a UPC code	
			if (r == d12) {	
				// is a upc code	
				System.out.println(input + " is a feasible UPC code");	
			}	
			else {	
				// not a upc code	
				System.out.println(input + " is an invalid UPC code");	
			}	
		}	
	}	
}