package contest; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.Arrays; import java.util.InputMismatchException; public class Q447 { InputStream is; PrintWriter out; String INPUT = ""; void solve() { long x1 = ni(), y1 = ni(); long x2 = ni(), y2 = ni(); long x3 = ni(), y3 = ni(); long x12 = crt(y1, x1, y2, x2); if(x12 == -1){ out.println(-1); return; } long y12 = y1/gcd(y1,y2)*y2; long ret = crt(y12, x12, y3, x3); if(ret == -1){ out.println(-1); return; } long y123 = y12/gcd(y12,y3)*y3; if(ret == 0)ret += y123; out.println(ret); } public static long gcd(long a, long b) { while (b > 0) { long c = a; a = b; b = c % b; } return a; } public static long crt(long p, long m, long q, long n) { long[] apr = exgcd(p, q); if((n - m) % apr[0] != 0)return -1; long mod = p * (q / apr[0]); long a = (mul(mul(apr[1], (n-m)/apr[0], mod), p, mod) + m) % mod; if(a < 0)a += mod; return a; } public static long[] exgcd(long a, long b) { if(a == 0 || b == 0)return null; int as = Long.signum(a); int bs = Long.signum(b); a = Math.abs(a); b = Math.abs(b); long p = 1, q = 0, r = 0, s = 1; while(b > 0){ long c = a / b; long d; d = a; a = b; b = d % b; d = p; p = q; q = d - c * q; d = r; r = s; s = d - c * s; } return new long[]{a, p * as, r * bs}; } public static long mul(long a, long b, long mod) { a %= mod; if(a < 0)a += mod; b %= mod; if(b < 0)b += mod; long ret = 0; int x = 63-Long.numberOfLeadingZeros(b); for(;x >= 0;x--){ ret += ret; if(ret >= mod)ret -= mod; if(b<<~x<0){ ret += a; if(ret >= mod)ret -= mod; } } return ret; } void run() throws Exception { is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()); out = new PrintWriter(System.out); long s = System.currentTimeMillis(); solve(); out.flush(); if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); } public static void main(String[] args) throws Exception { new Q447().run(); } private byte[] inbuf = new byte[1024]; private int lenbuf = 0, ptrbuf = 0; private int readByte() { if(lenbuf == -1)throw new InputMismatchException(); if(ptrbuf >= lenbuf){ ptrbuf = 0; try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } if(lenbuf <= 0)return -1; } return inbuf[ptrbuf++]; } private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } private double nd() { return Double.parseDouble(ns()); } private char nc() { return (char)skip(); } private String ns() { int b = skip(); StringBuilder sb = new StringBuilder(); while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ') sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } private char[] ns(int n) { char[] buf = new char[n]; int b = skip(), p = 0; while(p < n && !(isSpaceChar(b))){ buf[p++] = (char)b; b = readByte(); } return n == p ? buf : Arrays.copyOf(buf, p); } private char[][] nm(int n, int m) { char[][] map = new char[n][]; for(int i = 0;i < n;i++)map[i] = ns(m); return map; } private int[] na(int n) { int[] a = new int[n]; for(int i = 0;i < n;i++)a[i] = ni(); return a; } private int ni() { int num = 0, b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private long nl() { long num = 0; int b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); } }