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: Accepted)

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

fn strtovec(origin_text: String) -> Vec<i32> {
    let res: Vec<i32> = origin_text
        .split_whitespace()
        .map(|x| x.parse().unwrap())
        .collect();
    res
}

fn exp1(x: i32, y: i32, z: i32) -> i32 {
    let mut n: i32 = 1;
    loop {
        if (z * (n + 1) + (y * n) > x) {
            break;
        }
        n += 1;
    }
    n - 1
}

fn main() {
    let text: String = read_line();
    let v: Vec<i32> = strtovec(text);
    println!("{}", exp1(v[0], v[1], v[2]));
}