import Foundation
func toTuple<T>(_ args: [T]) -> (T, T, T) { (args[0], args[1], args[2]) }
func readInts() -> [Int] { readLine()!.split(separator: " ").map { Int($0)! } }

let (x, y, z) = toTuple(readInts())
print((x - z) / (y + z))