#include <iostream>
#include <algorithm>
#include <string.h>
#include <stdio.h>
int sum_of_digit(int n)
{
int rem, sum=0;
while(n!=0) {
rem = n%10;
n = n/10;
sum+=rem;
}
return sum;
}
int check_zero(int n)
{
int rem;
rem = n%10;
if(rem==0) return 1;
else return 0;
}
using namespace std;
int main()
{
// freopen("input.txt", "r", stdin);
string credit;
char ch[] = " ";
int i, dsum, usum, int_digit, digit_double, total_sum;
while(getline(cin, credit, '\n')!='\0') {
dsum=0;
usum=0;
// Algorithm for Deleting Space
for(i=0; i<strlen(ch); ++i) {
credit.erase(remove(credit.begin(), credit.end(), ch[i]), credit.end());
}
for(i=0; i<credit.size(); i+=2) {
int_digit = credit[i]-'0';
digit_double = int_digit*2;
if(digit_double>=10) {
dsum+=sum_of_digit(digit_double);
}
else dsum+=digit_double;
}
for(i=1; i<credit.size(); i+=2) {
int_digit = credit[i]-'0';
usum = usum+int_digit;
}
total_sum = dsum+usum;
// cout<<dsum<<endl;
// cout<<usum<<endl;
// cout<<total_sum<<endl;
if(check_zero(total_sum)) printf("Valid\n");
else printf("Invalid\n");
}
return 0;
}