package main

import (
        "fmt"
)

func Gcd(x int, y int) int {
        if y == 0 {
                return x
        } else {
                return Gcd(y, x%y)
        }
}

func main() {
        var x, y, gcd, ans int
        fmt.Scan(&ans, &gcd)
        f := 0
        for i := 0; i < 2; i++ {
                fmt.Scan(&x, &y)
                j := 0
                for ; ans%y != x && j <= gcd; j++ {
                        ans += gcd
                }
                if j == gcd+1 {
                        f = 1
                }
                gcd = gcd * y / Gcd(gcd, y)
        }
        if f == 1 {
                fmt.Println(-1)
        } else {
                fmt.Println(ans)
        }
}