use std::io;
fn main() {
    let nums = input_nums();
    let (a, b, c, d) = (nums[0], nums[1], nums[2], nums[3]);
    let (range_min, range_max) = (a + c, b + d);
    let m = nums[4];

    let mut mod_max = b + d;

    if mod_max < m {
        println!("{}", mod_max);
        return;
    }

    mod_max = 0;
    let lower = if range_max - m < range_min {
        range_min
    } else {
        range_max - m
    };

    for i in lower..range_max {
        if i % m > mod_max {
            mod_max = i % m;
        }
    }
    println!("{}", mod_max);
}

fn input_nums() -> Vec<i32> {
    let mut s = String::new();
    io::stdin().read_line(&mut s).unwrap();
    let mut v: Vec<i32> = Vec::new();
    for i in s.trim().split_whitespace() {
        v.push(i.parse().unwrap())
    }
    v
}