Задача A. RMQ

#include <iostream>
#include <cmath>
#include <vector>
#include <set>
#include <string>
#include <algorithm>
using namespace std;
using ll = long long;
void cv(vector <ll> v){
    for (auto x: v) cout<<x<<' ';
    cout<<'\n';
}

ll inf = pow(2, 32);
vector <ll> ar(1);
vector <pair<ll,ll>> qr(1);
struct sct{
    ll l, r, mn, mx;
};

void csc(sct f){
    cout<<f.l<<'-'<<f.r<<"  ";
    //cout<<f.mn<<'/'<<f.mx<<'\n';
}
vector <vector <sct> > wrk;

vector <sct> power;
sct sm;
void make(){
    int lvl = 1, lst_lvl;
    int l,r;
    while (pow(2,lvl) <= ar.size()){
        lst_lvl = lvl / 2;
        int lst_lvl = pow(2, lst_lvl);
        //cout<<"lvl = "<<lvl<<'\n';
        vector <sct> last = wrk[wrk.size() - 1];
        //cv(ar);
        /*cout<<"last:\n";
        for (auto x: last) csc(x);
        cout<<'\n';*/
        int len = pow(2, lvl);
        int hlf = len / 2;
        for (int i = 0;i<=ar.size()-len;++i){
            //cv(ar);
            l = i;
            r = i + len - 1;
            //cout<<ar[l]<<' '<<ar[r]<<'\n';
            //cout<<"l = "<<l<<" r = "<<r<<'\n';
            sct L = last[l];
            sct R = last[l+hlf];
            sm = {l, r, min(L.mn, R.mn), max(L.mx, R.mx)};
            power.push_back(sm);
            /*csc(L);
            csc(R);
            csc(sm);
            cout<<'\n';*/
        }
        /*cout<<"power:\n";
        for (auto x: power){
            csc(x);
        }
        cout<<'\n';*/
        wrk.push_back(power);
        power.clear();
        //cout<<"sz = "<<wrk.size()<<'\n';
        //cout<<"\n\n\n\n";
        lvl++;
    }
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll N,M,A,B;
    while (true){
        cin>>N>>M>>A>>B;
        //cin>>N>>M>>A>>B;
        if (N==0 && M==0 && A==0 && B==0) break;
        ar.clear();
        qr.clear();
        ll d;
        ll d1, d2;
        for (int i = 1;i<=N+M*2;++i){
            if (i <= N){
                d = ( ((A % inf) * (i % inf)) % inf + (B % inf) ) % inf;
                ar.push_back(d);
               /* cout<<d<<'\n';
                if (d == rl[i-1]) cout<<"OK\n";
                else cout<<"NO\n";*/
            }
            else{
                d1 = ( ((A % inf) * (i % inf)) % inf + (B % inf) ) % inf % N;
                d1++;
                i++;
                d2 = ( ((A % inf) * (i % inf)) % inf + (B % inf) ) % inf % N;
                d2++;
                qr.push_back({d1, d2});
                /*cout<<d1<<' '<<d2<<'\n';
                if (d1 == qr[id].first && d2 == qr[id].second){
                    cout<<"OK\n";
                }else{
                    cout<<"NO\n";
                }*/
                //id++;
            }
        }
        //cout<<'\n';
        //cv(ar);
        for (int i = 0; i < ar.size();++i){
            sm = {i, i, ar[i], ar[i]};
            //cout<<ar[i]<<'\n';
            //csc(sm);
            power.push_back(sm);
        }
        wrk.push_back(power);
        power.clear();
        //cout<<'\n'<<'\n';
        make();
        ll ans;
        ll tot = 0;
        /*cout<<"wrk\n";
        for (int q=0;q<wrk.size();++q) {
            cout<<"pow= "<<q<<'\n';
            for (auto y: wrk[q]){
                csc(y);
            }cout<<'\n';
        }cout<<'\n';*/
        for (auto Q: qr){
            int a = min(Q.first, Q.second);
            int b = max(Q.first, Q.second);
            a--;
            b--;
            //cout<<a<<' '<<b<<'\n';
            //cout<<b - a + 1<<'\n';
            int LVL = floor(log(b-a+1) / log(2));
            //cout<<"LVL = "<<LVL<<'\n';
            vector <sct> now = wrk[LVL];
            sct lft = now[a];
            sct rgt = now[b - pow(2,LVL) + 1];
            ans = min(lft.mn, rgt.mn);
            tot += ans;
            //cout<<a<<' '<<b - pow(2,LVL) + 1<<'\n'<<'\n';
        }
        cout<<tot<<'\n';
        wrk.clear();
    }

}