using System; using System.Linq; using System.Text.RegularExpressions; using System.Collections.Generic; using Debug = System.Diagnostics.Debug; using StringBuilder = System.Text.StringBuilder; using System.Numerics; namespace Program { public class Solver { public void Solve() { var a = new BigInteger[3]; for (long i = 0; i < 3; i++) a[i] = 1; var b = new BigInteger[3]; var mod = new BigInteger[3]; for (long i = 0; i < 3; i++) { b[i] = sc.Integer(); mod[i] = sc.Integer(); } var ans = MathEX.LiniearCongruence(a, b, mod); if (ans.Key <= 0) IO.Printer.Out.WriteLine(-1); else IO.Printer.Out.WriteLine(ans.Key); } public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput()); static T[] Enumerate(int n, Func f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; } } } #region Ex namespace Program.IO { using System.IO; using System.Text; using System.Globalization; public class Printer : StreamWriter { static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; } public static Printer Out { get; set; } public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } } public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { } public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { } public void Write(string format, IEnumerable source) { base.Write(format, source.OfType().ToArray()); } public void WriteLine(string format, IEnumerable source) { base.WriteLine(format, source.OfType().ToArray()); } } public class StreamScanner { public StreamScanner(Stream stream) { str = stream; } public readonly Stream str; private readonly byte[] buf = new byte[1024]; private int len, ptr; public bool isEof = false; public bool IsEndOfStream { get { return isEof; } } private byte read() { if (isEof) return 0; if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } } return buf[ptr++]; } public char Char() { byte b = 0; do b = read(); while (b < 33 || 126 < b); return (char)b; } public string Scan() { var sb = new StringBuilder(); for (var b = Char(); b >= 33 && b <= 126; b = (char)read()) sb.Append(b); return sb.ToString(); } public long Long() { if (isEof) return long.MinValue; long ret = 0; byte b = 0; var ng = false; do b = read(); while (b != '-' && (b < '0' || '9' < b)); if (b == '-') { ng = true; b = read(); } for (; true; b = read()) { if (b < '0' || '9' < b) return ng ? -ret : ret; else ret = ret * 10 + b - '0'; } } public int Integer() { return (isEof) ? int.MinValue : (int)Long(); } public double Double() { return double.Parse(Scan(), CultureInfo.InvariantCulture); } private T[] enumerate(int n, Func f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(); return a; } public char[] Char(int n) { return enumerate(n, Char); } public string[] Scan(int n) { return enumerate(n, Scan); } public double[] Double(int n) { return enumerate(n, Double); } public int[] Integer(int n) { return enumerate(n, Integer); } public long[] Long(int n) { return enumerate(n, Long); } } } static class Ex { static public string AsString(this IEnumerable ie) { return new string(System.Linq.Enumerable.ToArray(ie)); } static public string AsJoinedString(this IEnumerable ie, string st = " ") { return string.Join(st, ie); } static public void Main() { var solver = new Program.Solver(); solver.Solve(); Program.IO.Printer.Out.Flush(); } } #endregion static public class MathEX { static public BigInteger GCD(BigInteger x, BigInteger y) { byte i = 0; while (x != 0 && y != 0) { if (i == 0) y %= x; else x %= y; i ^= 1; } return x == 0 ? y : x; } //O(log n) //ax+by=gcd(a,b),return x,y static public BigInteger ExGCD(BigInteger a, BigInteger b, out BigInteger x, out BigInteger y) { var u = new BigInteger[] { a, 1, 0 }; var v = new BigInteger[] { b, 0, 1 }; while (v[0] != 0) { var t = u[0] / v[0]; for (int i = 0; i < 3; i++) { var tmp = u[i] - t * v[i]; u[i] = v[i]; v[i] = tmp; } } x = u[1]; y = u[2]; if (u[0] > 0) return u[0]; for (long i = 0; i < 3; i++) u[i] = -u[i]; return u[0]; } static public BigInteger Inverse(BigInteger num, BigInteger mod) { BigInteger p, q; ExGCD(num, mod, out p, out q); return (p % mod + mod) % mod; } static public KeyValuePair LiniearCongruence(BigInteger[] A, BigInteger[] B, BigInteger[] M) { BigInteger x = 0; BigInteger m = 1; var n = A.Length; for (int i = 0; i < n; i++) { var a = A[i] * m; var b = B[i] - A[i] * x; var d = GCD(M[i], a); if (b % d != 0) return new KeyValuePair(0, -1); var t = ((b / d) * Inverse(a / d, M[i] / d)) % (M[i] / d); x = x + m * t; m *= M[i] / d; } if (x % m < 0) x = x % m + m; return new KeyValuePair(x % m, m); } }