import std.conv, std.functional, std.range, std.stdio, std.string; import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons; import core.bitop; class EOFException : Throwable { this() { super("EOF"); } } string[] tokens; string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; } int readInt() { return readToken.to!int; } long readLong() { return readToken.to!long; } real readReal() { return readToken.to!real; } bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } } bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } } int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; } int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); } int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); } long rev(long a) { char[] s = a.to!string.dup; s.reverse; return s.to!long; } void main() { try { for (; ; ) { const P = readLong; const Q = readLong; const X = readLong; const Y = readLong; // rev: q 0...0 y long q = Q; for (; q % 10 == 0 || rev(q) % P == X; q += Q) {} long y = Y; for (; y % 10 == 0 || rev(y) % P == 0; y += Q) {} debug { writeln("q = ", q, ", y = ", y); } const a = rev(y) % P; long r = rev(q) % P; int cnt; long ten = (10L^^(q.to!string.length)) % P; for (; (ten * a + r) % P != X; ) { ++cnt; ten = (ten * 10) % P; } char[] ans; ans ~= q.to!string; ans ~= '0'.repeat(cnt).array; ans ~= y.to!string; debug { assert(BigInt(ans) % Q == Y); } ans.reverse; debug { assert(BigInt(ans) % P == X); } writeln(ans); } } catch (EOFException e) { } }