Problem:
Score : 200 points

Problem Statement

Some number of chocolate pieces were prepared for a training camp.
The camp had N participants and lasted for D days.
The i-th participant (1 \leq i \leq N) ate one chocolate piece on each of the following days in the camp: the 1-st day, the (A_i + 1)-th day, the (2A_i + 1)-th day, and so on.
As a result, there were X chocolate pieces remaining at the end of the camp. During the camp, nobody except the participants ate chocolate pieces.

Find the number of chocolate pieces prepared at the beginning of the camp.

Constraints

1 \leq N \leq 100

1 \leq D \leq 100

1 \leq X \leq 100

1 \leq A_i \leq 100 (1 \leq i \leq N)

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
D X
A_1
A_2
:
A_N

Output

Find the number of chocolate pieces prepared at the beginning of the camp.

Sample Input 1

3
7 1
2
5
10

Sample Output 1

8

The camp has 3 participants and lasts for 7 days.
Each participant eats chocolate pieces as follows:

The first participant eats one chocolate piece on Day 1, 3, 5 and 7, for a total of four.

The second participant eats one chocolate piece on Day 1 and 6, for a total of two.

The third participant eats one chocolate piece only on Day 1, for a total of one.

Since the number of pieces remaining at the end of the camp is one, the number of pieces prepared at the beginning of the camp is 1 + 4 + 2 + 1 = 8.

Sample Input 2

2
8 20
1
10

Sample Output 2

29

Sample Input 3

5
30 44
26
18
81
18
6

Sample Output 3

56

Solution in Rust (1.42.0) (judge verdict: Accepted)

#[allow(unused_macros, dead_code)]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

#[allow(unused_macros, dead_code)]
macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };

    ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

#[allow(unused_macros, dead_code)]
macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, bytes) => {
        read_value!($next, String).into_bytes()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

#[allow(dead_code)]
struct UnionFind {
    parent: Vec<usize>,
    rank: Vec<usize>,
    size: Vec<usize>,
}

#[allow(dead_code)]
impl UnionFind {
    fn new(n: usize) -> UnionFind {
        let mut p = vec![0; n];
        for i in 0..n {
            p[i] = i;
        }
        return UnionFind {
            parent: p,
            rank: vec![0; n],
            size: vec![1; n],
        };
    }

    fn find(&mut self, x: usize) -> usize {
        if x == self.parent[x] {
            x
        } else {
            let p = self.parent[x];
            let pr = self.find(p);
            self.parent[x] = pr;
            pr
        }
    }

    fn same(&mut self, a: usize, b: usize) -> bool {
        self.find(a) == self.find(b)
    }

    fn unite(&mut self, a: usize, b: usize) {
        let a_root = self.find(a);
        let b_root = self.find(b);
        if a_root == b_root {
            return;
        }
        if self.rank[a_root] > self.rank[b_root] {
            self.parent[b_root] = a_root;
            self.size[a_root] += self.size[b_root];
        } else {
            self.parent[a_root] = b_root;
            self.size[b_root] += self.size[a_root];
            if self.rank[a_root] == self.rank[b_root] {
                self.rank[b_root] += 1;
            }
        }
    }

    fn get_size(&mut self, x: usize) -> usize {
        let root = self.find(x);
        self.size[root]
    }
}

const MOD_P: usize = 1000000007;

#[allow(dead_code)]
// fact(n) = n! mod p
fn fact(n: usize) -> usize {
    let mut acc = 1;
    for i in 1..n + 1 {
        acc = acc * i % MOD_P;
    }
    acc
}

#[allow(dead_code)]
fn mod_pow(b: usize, mut e: usize) -> usize {
    let mut base = b;
    let mut acc = 1;

    while e > 1 {
        if e % 2 == 1 {
            acc = acc * base % MOD_P;
        }
        e /= 2;
        base = base * base % MOD_P;
    }

    if e == 1 {
        acc = acc * base % MOD_P;
    }

    acc
}

#[allow(dead_code)]
fn comb(n: usize, r: usize) -> usize {
    // nCr = n! / (r! (n-r)!) = n! (r!)^(p-2) ((n-r)!)^(p-2)
    let x = ((n - r + 1)..(n + 1)).fold(1, |p, x| p * x % MOD_P);
    let y = mod_pow(fact(r), MOD_P - 2);
    x * y % MOD_P
}

#[derive(Clone, Copy, Debug)]
struct GF(usize);

impl std::ops::Add for GF {
    type Output = GF;
    fn add(self, rhs: GF) -> Self::Output {
        let mut d = self.0 + rhs.0;
        if d >= MOD_P {
            d -= MOD_P;
        }
        GF(d)
    }
}

impl std::ops::AddAssign for GF {
    fn add_assign(&mut self, rhs: GF) {
        *self = *self + rhs;
    }
}

impl std::ops::Sub for GF {
    type Output = GF;
    fn sub(self, rhs: GF) -> Self::Output {
        let mut d = self.0 + MOD_P - rhs.0;
        if d >= MOD_P {
            d -= MOD_P;
        }
        GF(d)
    }
}

impl std::ops::SubAssign for GF {
    fn sub_assign(&mut self, rhs: GF) {
        *self = *self - rhs;
    }
}

impl std::ops::Mul for GF {
    type Output = GF;
    fn mul(self, rhs: GF) -> Self::Output {
        let mut d = self.0 * rhs.0;
        d %= MOD_P;
        GF(d)
    }
}

impl std::ops::MulAssign for GF {
    fn mul_assign(&mut self, rhs: GF) {
        *self = *self * rhs;
    }
}

impl std::fmt::Display for GF {
    fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result {
        write!(f, "{}", self.0)
    }
}

#[allow(dead_code)]
impl GF {
    pub fn new(n: usize) -> GF {
        GF(n % MOD_P)
    }
    pub fn zero() -> GF {
        GF(0)
    }
    pub fn one() -> GF {
        GF(1)
    }
    pub fn pow(self, mut e: usize) -> GF {
        let mut acc = GF::one();
        let mut b = self;
        while e > 1 {
            if e % 2 == 1 {
                acc *= b;
            }
            b *= b;
            e /= 2;
        }
        if e == 1 {
            acc *= b;
        }
        acc
    }
    pub fn fact(self) -> GF {
        let mut acc = GF::one();
        for i in 1..=self.0 {
            acc *= GF::new(i);
        }
        acc
    }
    pub fn inv(self) -> GF {
        self.pow(MOD_P - 2)
    }
    pub fn comb(n: GF, r: GF) -> GF {
        // nCr = n! / (r! (n-r)!) = n! (r!)^(p-2) ((n-r)!)^(p-2)
        let x = ((n.0 - r.0 + 1)..=n.0).fold(GF::one(), |p, x| p * GF(x));
        let y = r.fact().inv();
        x * y
    }
}

#[allow(dead_code)]
#[derive(Debug)]
struct MemComb {
    inv: Vec<GF>,
    fact: Vec<GF>,
    factinv: Vec<GF>,
}

#[allow(dead_code)]
impl MemComb {
    pub fn new(n: usize) -> MemComb {
        let mut inv = vec![GF::one(); n + 1];
        let mut fact = vec![GF::one(); n + 1];
        let mut factinv = vec![GF::one(); n + 1];

        for i in 2..=n {
            fact[i] = fact[i - 1] * GF(i);
        }

        factinv[n] = fact[n].inv();
        for i in (1..n).rev() {
            factinv[i] = factinv[i + 1] * GF(i + 1); // 1/n! = 1/(n+1)! * (n+1)
            inv[i] = factinv[i] * fact[i - 1]; // 1/n = 1/n! * (n-1)!
        }
        inv[n] = factinv[n] * fact[n - 1];

        MemComb { inv, fact, factinv }
    }
}

#[allow(dead_code)]
fn gcd(a: usize, b: usize) -> usize {
    if b > a {
        gcd(b, a)
    } else if a % b == 0 {
        b
    } else {
        gcd(b, a % b)
    }
}

#[allow(dead_code)]
fn getline() -> String {
    let mut __ret = String::new();
    std::io::stdin().read_line(&mut __ret).ok();
    return __ret;
}

#[allow(unused_imports)]
use std::cmp::{max, min};

fn main() {
    input! {
        n: usize,
        d: usize,
        x: usize,
        a: [usize;n],
    }
    let ans = x + a.iter().fold(0, |acc, &y| acc + (d + y - 1) / y);
    println!("{}", ans);
}