#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
const ll MOD1000000007 = 1000000007;
const ll MOD998244353 = 998244353;
const ll MOD[3] = {999727999, 1070777777, 1000000007};
const ll LINF = 1LL << 60;
const int IINF = 1 << 30 - 1;

template<typename T> struct Edge{
    int to; T w;
    Edge(int to_, T w_=1){
        to = to_;
        w=w_;
    }
};
template<typename T> using Tree = vector<vector<Edge<T>>>;
template<typename T> using Graph = vector<vector<Edge<T>>>;
/* 容量&重み付きエッジ for Dinic */
template<typename T> struct REdge{
    int to;
    T cap;
    T cost;
    int rev;
    REdge(int to_, T cap_, T cost_=1){
        to = to_;
        cap = cap_;
        cost = cost_;
    }
    
    REdge(int to_, T cap_, T cost_, int rev_){
        to = to_;
        cap = cap_;
        cost = cost_;
        rev = rev_;
    }
};

/* 残余グラフ for Dinic */
template<typename T> using RGraph = vector<vector<REdge<T>>>;

ll pow_mod(ll x, ll n, ll mod){
    ll ret = 1;
    while(n > 0){
        if(n & 1) ret = (ret*x)%mod;
        x = x*x%mod;
        n >>=1;
    }
    return ret;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    ll n, m, p, q; cin >> n >> m >> p >> q;
    while(q--){
        ll x, f; cin >> x >> f;
        ll inv_x = pow_mod(x%p, p-2, p);
        ll mod_y = f * inv_x % p;
        ll ans = m/p;
        if(mod_y <= m%p) ans++;
        if(mod_y==0) ans--;
        cout << ans << '\n';
    }

    
}