Problem:
Score : 200 points

Problem Statement

We ask you to select some number of positive integers, and calculate the sum of them.

It is allowed to select as many integers as you like, and as large integers as you wish.
You have to follow these, however: each selected integer needs to be a multiple of A, and you need to select at least one integer.

Your objective is to make the sum congruent to C modulo B.
Determine whether this is possible.

If the objective is achievable, print YES. Otherwise, print NO.

Constraints

1 ≤ A ≤ 100

1 ≤ B ≤ 100

0 ≤ C < B

Input

Input is given from Standard Input in the following format:

A B C

Output

Print YES or NO.

Sample Input 1

7 5 1

Sample Output 1

YES

For example, if you select 7 and 14, the sum 21 is congruent to 1 modulo 5.

Sample Input 2

2 2 1

Sample Output 2

NO

The sum of even numbers, no matter how many, is never odd.

Sample Input 3

1 100 97

Sample Output 3

YES

You can select 97, since you may select multiples of 1, that is, all integers.

Sample Input 4

40 98 58

Sample Output 4

YES

Sample Input 5

77 42 36

Sample Output 5

NO

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
#if !DEBUG
    using System.IO;
#endif

public class Program {
    public static void Main() {
        #region SetAutoFlushIsFalse
#if !DEBUG
        var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
        Console.SetOut(sw);
#endif
        #endregion
        var arr = ReadLib.ReadAsIntArray();
        var a = arr[0];
        var b = arr[1];
        var c = arr[2];

        var val = CalcValue(a, b, c);


        Console.WriteLine(val);
        #region Flush
#if !DEBUG
        Console.Out.Flush();
        sw.Close();
#endif
        #endregion
    }

    private static string CalcValue(int a, int b, int c) {
        if (a == 1) {
            return "YES";
        }

        var mod = a % b;
        if (mod == 0) {
            return c == 0 ? "YES" : "NO";
        }

        HashSet<int> modHistory = new HashSet<int>();
        while (true) {
            mod = (mod + a) % b;
            if (mod == c) {
                return "YES";
            }
            if (!modHistory.Add(mod)) {
                return "NO";
            }
        }
    }
}

static class ReadLib {
    public static long ReadAsLong() {
        return long.Parse(Console.ReadLine());
    }

    public static int ReadAsInt() {
        return int.Parse(Console.ReadLine());
    }

    public static int[] ReadAsIntArray() {
        return Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
    }

    public static long[] ReadAsLongArray() {
        return Console.ReadLine().Split(' ').Select(s => long.Parse(s)).ToArray();
    }

    public static ulong[] ReadAsULongArray() {
        return Console.ReadLine().Split(' ').Select(s => ulong.Parse(s)).ToArray();
    }

    public static string[] ReadAsStringArray() {
        return Console.ReadLine().Split(' ');
    }

    public static int[] ReadNTimesAsInt(int n) {
        return Enumerable.Range(1, n).Select(s => int.Parse(Console.ReadLine())).ToArray();
    }

    public static int[][] ReadNTimesAsIntArray(int n) {
        return Enumerable.Range(1, n).Select(s => ReadAsIntArray()).ToArray();
    }

}

static class MyMath {
    /// <summary>階乗</summary>
    public static long Factorial(int n) {
        if (n == 0) {
            return 1;
        }

        return Permutation(n, 0);
    }

    public static long Permutation(int n, int k) {
        return Enumerable.Range(0, n - k).Select(i => n - i).Aggregate(1, (b, i) => b * i);
    }

    /// <summary>nCr, 組み合わせ</summary>
    public static long Combination(int n, int r) {
        if (r == 0) {
            return 1;
        }
        // 分子
        var moleculeArr = Enumerable
            .Range(0, Math.Min(n - r, r))
            .Select(i => n - i)
            .ToArray();
        var moleculeArrLength = moleculeArr.Length;
        // 分母
        var denominatorArr = Enumerable
            .Range(1, Math.Max(n - r, r))
            .ToArray();

        for (var m = 0; m < moleculeArrLength; m++) {
            while (true) {
                var mVal = moleculeArr[m];
                var gcds = denominatorArr.Select(b => Gcd(mVal, b));
                var maxGcd = gcds.Max();
                var maxI = gcds.ToList().IndexOf(maxGcd);

                if (maxGcd == 1) {
                    break;
                }

                denominatorArr[maxI] /= maxGcd;
                moleculeArr[m] /= maxGcd;
            }
        }

        return FullPower(moleculeArr);
    }

    #region FullPower
    /// <summary>総乗、π</summary>
    public static long FullPower(IEnumerable<long> vs) {
        return vs.Aggregate(1L, (a, b) => a * b);
    }

    public static long FullPower(IEnumerable<int> vs) {
        return vs.Aggregate(1L, (a, b) => a * b);
    }
    #endregion

    /// <summary>最大公約数</summary>
    public static int Gcd(long item1, long item2) {
        var a = Math.Max(item1, item2);
        var b = Math.Min(item1, item2);

        while (true) {
            var mod = a % b;
            if (mod == 0) {
                break;
            }

            a = b;
            b = mod;
        }
        return (int)b;
    }

    /// <summary>約分。最大公約数で割ったものを返す。</summary>
    public static Tuple<long, long> DeviedByGcd(long item1, long item2) {
        var gcd = Gcd(item1, item2);
        return new Tuple<long, long>(item1 / gcd, item2 / gcd);
    }
}

//static class IEnumerableExtention {
//    public static int IndexOfMax<T>(this IEnumerable<T> ts) {
//        var max = ts.Max();
//        return ts.ToList().IndexOf(max);
//    }

//    public static int IndexOfMax<T>(this IEnumerable<T> ts, Func<T, int> func) {
//        var funced = ts.Select(i => func(i));
//        var max = ts.Max(func);
//        return funced.ToList().IndexOf(max);
//    }

//    public static int IndexOfMax<T>(this IEnumerable<T> ts, Func<T, long> func) {
//        var funced = ts.Select(i => func(i));
//        var max = ts.Max(func);
//        return funced.ToList().IndexOf(max);
//    }
//}