fun readInt () =
    valOf (TextIO.scanStream (Int.scan StringCvt.DEC) TextIO.stdIn)


val () =
    let
        val a = readInt ()
        val b = readInt ()
        val c = readInt ()
        val d = readInt ()

        val ans = if a = 0 then d div b
                  else if b = 0 then c div a
                  else Int.min (c div a, d div b)
    in
        print (Int.toString ans ^ "\n")
    end