// 尺取りしろという話だがどういうことか

use std::io::Write;
use std::collections::*;

type Map<K, V> = BTreeMap<K, V>;
type Set<T> = BTreeSet<T>;
type Deque<T> = VecDeque<T>;

fn main() {
    input! {
        n: usize,
        k: i64,
        m: i64,
        b: [i64; n],
        c: [i64; n],
    }
    let mut deq = Deque::<(i64, i64)>::new();
    let mut cnt = 0;
    let mut sum = 0;
    let mut ans = 0;
    for (mut c, b) in b.into_iter().zip(c) {
        while deq.len() > 0 && cnt - deq[0].0 + c >= k {
            let (p, q) = deq[0];
            // 0 <= i < q, sum + (b - p)i = 0 (mod M)
            let (x, y, g) = ext_gcd(m, b - p);
            if sum % g == 0 {
                let i = ((-sum / g) * y).rem_euclid(m / g);
                if i < q {
                    ans += (q - i - 1) / (m / g) + 1;
                }
            }
            deq.pop_front();
            cnt -= q;
            sum = (sum + m - p * q % m) % m;
        }
        if cnt + c > k && deq.len() > 0 {
            let need = cnt + c - k;
            let (p, q) = deq[0];
            assert!(need < q);
            deq[0].1 -= need;
            let q = need;
            // 0 <= i < q, sum + (b - p)i = 0 (mod M)
            let (x, y, g) = ext_gcd(m, b - p);
            if sum % g == 0 {
                let i = ((-sum / g) * y).rem_euclid(m / g);
                if i < q {
                    ans += (q - i - 1) / (m / g) + 1;
                }
            }
            cnt -= q;
            sum = (sum + m - p * q % m) % m;
        }
        if c > k {
            if k * b % m == 0 {
                ans += c - k;
            }
            c = k;
        }
        deq.push_back((b, c));
        cnt += b;
        sum = (sum + b * c) % m;
    }
    if sum % m == 0 {
        ans += 1;
    }
    println!("{}", ans);
}

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

#[macro_export]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[macro_export]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------
// return (a, b, g)
// ax + by = gcd(x, y)
// gcd(x, y) = 0 の時は(0, 0) が返る
pub fn ext_gcd(x: i64, y: i64) -> (i64, i64, i64) {
    if y == 0 {
        return (x.signum(), 0, x.abs());
    }
    let q = x.div_euclid(y);
    let r = x.rem_euclid(y);
    let p = ext_gcd(y, r);
    (p.1, p.0 - q * p.1, p.2)
}