use std::collections::HashMap;


fn main() {
    let mut nkm = String::new();
    std::io::stdin().read_line(&mut nkm).ok();
    let nkm: Vec<usize> = nkm.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nkm[0];
    let k = nkm[1];
    let m = nkm[2];

    let mut factors = HashMap::new();
    let mut base = m;
    for i in 2..=(m as f64).sqrt().floor() as usize {
        while base % i == 0 {
            base /= i;
            *factors.entry(i).or_insert(0usize) += 1;
        }
    }
    if base > 1 { factors.insert(base, 1); }
    let startn = n - k;
    let endn = n;
    let startd = 0;
    let endd = k;
    let mut result = 1usize << 60;
    for (&val, &cnt) in factors.iter() {
        let mut num_cnt = 0usize;
        let mut denom_cnt = 0usize;
        let mut base = val;
        while endd / base > startd / base {
            denom_cnt += endd / base - startd / base;
            base *= val;
        }
        let mut base = val;
        while endn / base > startn / base {
            num_cnt += endn / base - startn / base;
            base *= val;
        }
        result = result.min((num_cnt - denom_cnt) / cnt);
    }
    println!("{}", result);
}