def main():
    A, B, C, D = map(int, input().split())
    for vegitable in range(A+1):
        if vegitable * C > B:
            break
        if vegitable * (C+1) > D:
            break
    else:
        print(vegitable)
        return
    print(vegitable-1)


if __name__ == "__main__":
    main()