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)

use std::io::*;

fn main() {
    let mut x = read();
    let y = read();
    let z = read();
    let mut count = 0;

    loop {
        x -= z;
        x -= y;
        if x - z - y > 0 {
            count += 1;
        } else {
            break;
        }
    }
        println!("{}", count);
}

// fn read_v() -> Vec<char> {
//     let s = stdin();
//     let b = s.bytes()
//         .map(|c| c.unwrap() as char)
//         .take_while(|c| !c.is_whitespace())
//         .collect::<Vec<char>>();
//     b
// }

fn read() -> i64 {
    let s = stdin();
    let b = s.bytes()
        .map(|c| c.unwrap() as char)
        .take_while(|c| !c.is_whitespace())
        .collect::<String>();
    b.parse().ok().expect("Failed read()")
}