use std::collections::hash_set::Iter;
use std::rc::Rc;
use std::ops::DivAssign;
use std::ops::MulAssign;
use std::ops::SubAssign;
use std::collections::BinaryHeap;
use std::str::FromStr;
use std::collections::HashSet;
use std::collections::BTreeMap;
use std::fmt::Display;
use std::ops::Neg;
use std::ops::Div;
use std::ops::Mul;
use std::ops::Add;
use std::ops::{AddAssign, Sub};
use std::cmp::max;
use std::collections::VecDeque;
use std::cmp::min;
use std::collections::{HashMap, BTreeSet};
use std::cmp::Ordering;
use std::fmt::Debug;

fn read_line() -> String {
    let mut buffer = String::new();
    std::io::stdin().read_line(&mut buffer).expect("No Line");
    buffer.trim().to_owned()
}
fn read_lines<T: std::str::FromStr>(count: usize) -> Vec<T> {
    let mut buffer = String::new();
    let mut vec = Vec::with_capacity(count);
    for _ in 0 .. count {
        std::io::stdin().read_line(&mut buffer).expect("No Line");
        vec.push(buffer.trim().parse().ok().expect("Can't Parse"));
        buffer.clear();
    }
    vec
}
fn read_tabulate<R, T: Fn(&str)->R> (count: usize, transformer: T) -> Vec<R> {
    let mut buffer = String::new();
    let mut vec = Vec::with_capacity(count);
    for _ in 0 .. count {
        std::io::stdin().read_line(&mut buffer).expect("No Line");
        vec.push(transformer(buffer.trim()));
        buffer.clear();
    }
    vec
}
fn read_value<T: std::str::FromStr>() -> T {
    read_line().trim().parse().ok().unwrap()
}
fn read_values<T: std::str::FromStr>() -> Vec<T> {
    read_line().trim().split_whitespace().map(|x| x.parse().ok().expect("Can't Parse")).collect::<Vec<T>>()
}
macro_rules! freeze {
    ($($id:ident), *) => {
        $(let $id = $id;)*
    };
}
macro_rules! read_map {
    ($ident: ident: [$block: block; $size: expr]) => {
        let $ident = (0 .. $size).into_iter().map(|_| $block).collect::<Vec<_>>();
    };
    (mut $ident: ident: [$block: block; $size: expr]) => {
        let mut $ident = (0 .. $size).into_iter().map(|_| $block).collect::<Vec<_>>();
    };
}
macro_rules! read {
    (mut $ident: ident: String) => {
        let mut $ident = read_value::<String>();
    };
    ($ident: ident: String) => {
        let $ident = read_value::<String>();
    };
    (mut $ident: ident: [$ty:ty]) => {
        let mut $ident = read_values::<$ty>();
    };
    ($ident: ident: [$ty:ty]) => {
        let $ident = read_values::<$ty>();
    };
    (mut $ident: ident: [[$ty:ty]; $size: expr]) => {
        let mut $ident = (0 .. $size).into_iter().map(|_| read_values::<$ty>()).collect::<Vec<_>>();
    };
    ($ident: ident: [[$ty:ty]; $size: expr]) => {
        let $ident = (0 .. $size).into_iter().map(|_| read_values::<$ty>()).collect::<Vec<_>>();
    };
    (mut $ident: ident: [$ty:ty; $size:expr]) => {
        let mut $ident = read_lines::<$ty>($size);
    };
    ($ident: ident: [$ty:ty; $size:expr]) => {
        let $ident = read_lines::<$ty>($size);
    };
    ($ident: ident: [$block: block; $size: expr]) => {
        let $ident = (0 .. $size).into_iter().map(|_| $block).collect::<Vec<_>>();
    };
    (mut $ident: ident: [$block: block; $size: expr]) => {
        let mut $ident = (0 .. $size).into_iter().map(|_| $block).collect::<Vec<_>>();
    };
    ($($token: tt)*) => {
        let mut iter = read_values::<String>().into_iter();
        read_from_iter!(iter; $($token)*);
    };
}
macro_rules! read_from_iter {
    ($iter:expr; mut $ident:ident:$ty:ty, $($rest:tt)*) => {
        let mut $ident = $iter.next().unwrap().parse::<$ty>().expect("Can't Parse");
        read_from_iter!($iter; $($rest)*);
    };
    ($iter:expr; $ident:ident:$ty:ty, $($rest:tt)*) => {
        let $ident = $iter.next().unwrap().parse::<$ty>().expect("Can't Parse");
        read_from_iter!($iter; $($rest)*);
    };
    ($iter:expr; mut $ident:ident:$ty:ty) => {
        let mut $ident = $iter.next().unwrap().parse::<$ty>().expect("Can't Parse");
    };
    ($iter:expr; $ident:ident:$ty:ty) => {
        let $ident = $iter.next().unwrap().parse::<$ty>().expect("Can't Parse");
    };
    ($iter: expr; ) => {};
}
struct KeyValue<K, V> {
    key: K,
    value: V
}
impl <K: PartialOrd, V> PartialEq for KeyValue<K, V> {
    fn eq(&self, other: &Self) -> bool {
        self.key.eq(&other.key)
    }
}
impl <K: PartialOrd, V> Eq for KeyValue<K, V> {}
impl <K: PartialOrd, V> PartialOrd for KeyValue<K, V> {
    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
        self.key.partial_cmp(&other.key)
    }
}
impl <K: PartialOrd, V> Ord for KeyValue<K, V> {
    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
        self.key.partial_cmp(&other.key).ok_or("Can't Compare").unwrap()
    }
}
fn count(p: i32, q: i32, num: i32, den: i32, min_d: i32, max_den: i32, rest: usize) -> usize {
    if p * den == q * num { return 1; }
    if p * den < q * num { return 0; }
    if rest == 0 { return 0; }
    let mut sum = 0;
    let mut d = max(min_d, q * den / (p * den - num * q));
    if den >= max_den / d + 1 { return 0}
    while d * den <= max_den {
        sum += count(p, q, num * d + den, den * d, d, max_den, rest - 1);
        d += 1;
    }
    sum    
}

fn main() {
    loop {
        read!(p: i32, q: i32, a: i32, n: usize);
        if p == 0 && q == 0 {break;}
        println!("{}", count(p, q, 0, 1, 1, a, n));
    }
}


Measured memory_bytes: 5044