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)

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

fn ans(length: i32, width: i32, interval: i32) -> i32 {
  (length - interval) / (width + interval)
}

fn main() {
  let nums: Vec<i32> 
    = read_line().split(" ").map(|x| x.parse().unwrap()).collect();
/*
  let tests = vec![
    vec![13, 3, 1, 3],
    vec![12, 3, 1, 2],
    vec![100000, 1, 1, 49999],
    vec![64146, 123, 456, 110],
    vec![64145, 123, 456, 109],
  ];
  for vec in &tests {
    let ans = ans(vec[0], vec[1], vec[2]);
    assert_eq!(ans, vec[3]);  
  }
*/
  println!("{}", ans(nums[0], nums[1], nums[2]));
}