Problem:
Score : 200 points

Problem Statement

We have a long seat of width X centimeters.
There are many people who wants to sit here. A person sitting on the seat will always occupy an interval of length Y centimeters.

We would like to seat as many people as possible, but they are all very shy, and there must be a gap of length at least Z centimeters between two people, and between the end of the seat and a person.

At most how many people can sit on the seat?

Constraints

All input values are integers.

1 \leq X, Y, Z \leq 10^5

Y+2Z \leq X

Input

Input is given from Standard Input in the following format:

X Y Z

Output

Print the answer.

Sample Input 1

13 3 1

Sample Output 1

3

There is just enough room for three, as shown below:

Figure

Sample Input 2

12 3 1

Sample Output 2

2

Sample Input 3

100000 1 1

Sample Output 3

49999

Sample Input 4

64146 123 456

Sample Output 4

110

Sample Input 5

64145 123 456

Sample Output 5

109

Solution in Rust (1.15.1) (judge verdict: Wrong Answer)

fn read_line() -> String {
    use std::io;
    let mut s = String::new();
    io::stdin().read_line(&mut s).unwrap();
    s
}

fn main() {
    let line = read_line();
    let mut iter = line.split_whitespace();
    let x:i64 = iter.next().unwrap().parse().unwrap();
    let y:i64 = iter.next().unwrap().parse().unwrap();
    let z:i64 = iter.next().unwrap().parse().unwrap();
    println!("{}", (x-1)/(y+z));
}