Number Theory for Maids

// Divisibility with specific ending digits by Dr. Eli Selig
// This code is CCO
// https://creativecommons.org/publicdomain/zero/1.0/legalcode.txt

import java.math.BigInteger;

public class Main {

    public static class MatchResult {
        public final BigInteger firstMatch;
        public final BigInteger stepSize;
        public MatchResult(BigInteger firstMatch, BigInteger stepSize) {
            this.firstMatch = firstMatch;
            this.stepSize = stepSize;
        }
        @Override
        public String toString() {
            return "First match: " + firstMatch + ", repeats every " + stepSize;
        }
    }

    public static MatchResult findMatch(int divisor1, int divisor2, int endingDigits) {
        BigInteger a = BigInteger.valueOf(divisor1);
        BigInteger b = BigInteger.valueOf(divisor2);
        BigInteger d = a.multiply(b).divide(a.gcd(b));
        BigInteger e = BigInteger.valueOf(endingDigits);
        int digits = String.valueOf(endingDigits).length();
        BigInteger m = BigInteger.TEN.pow(digits);

        if (!e.mod(d.gcd(m)).equals(BigInteger.ZERO)) {
            System.out.println("No solution.");
            return null;
        }

        BigInteger n = e;
        while (!n.mod(d).equals(BigInteger.ZERO))
            n = n.add(m);
        return new MatchResult(n, d.multiply(m).divide(d.gcd(m)));
    }

    public static void main(String[] args) {
        MatchResult result = findMatch(567, 33, 567);
        if (result != null)
            System.out.println(result);
    }
}