// No.2099 [Cherry Alpha B] Time Machine
package main

import (
	"fmt"
	"math"
)

func main() {
	var T, X, A, B, Y int
	for {
		fmt.Scan(&T)
		fmt.Scan(&X, &A)
		fmt.Scan(&Y, &B)

		var t, d int
		if T >= 0 {
			i := T / A
			t = T % A
			d = i * X
		} else {
			i := (-T + B - 1) / B
			t = T + i*B
			d = i * Y
		}

		mind := math.MaxInt
		var f func(t, d int)
		f = func(t, d int) {
			if d > mind {
				return
			}
			if t == 0 {
				if d < mind {
					mind = d
				}
				return
			}

			if t > 0 {
				f(0, d+t)
				f(t-A, d+X)
			} else {
				f(t+B, d+Y)
			}
		}
		f(t, d)
		fmt.Println(mind)
	}
}