book-of-portion-making.cpp

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ff first
#define ss second
#define mp make_pair
#define pb push_back
const int N = 2e5 + 11;

void solve() {
	string s;
	cin >> s;
	ll sum = 0;

	for (int i = 1; i <= s.size(); i++)
		sum += (s[i - 1] - '0') * i;

	cout <<  (sum % 11) ? "Illegal ISBN" : "Legal ISBN" << endl;
}

int main() {
	freopen("input.txt", "r", stdin);
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int no_of_test_cases = 1;
	cin >> no_of_test_cases;
	while (no_of_test_cases--)solve();
	return 0;
}