#include<iostream>
#include<iomanip>
#include<cstdio>
#include<cstdlib>
#include<cassert>

#include<cmath>
#include<functional>
#include<algorithm>

#include<vector>
#include<string>
#include<queue>
#include<stack>
#include<deque>
#include<set>
#include<unordered_set>
#include<map>
#include<unordered_map>
#include<bitset>
#include<tuple>

#define TEST {IS_TEST=true;}
#define fi first
#define se second
#define pb(x) {push_back(x);}

using namespace std;
using ll = int_fast64_t;
using v_b = vector <bool>; using v_ll = vector <ll>; using str = string; using v_str = vector <string>; using p_ll = pair < ll,ll >;
using vv_b = vector < v_b >; using vv_ll = vector < v_ll >; using vp_ll = vector < p_ll >;
using vvv_ll = vector < vv_ll >; using vvp_ll = vector < vp_ll >;
using ld = long double; using v_ld = vector <ld>; using vv_ld = vector<v_ld>;

bool IS_TEST=false;
ll ll_min64=1LL<<63;
ll ll_max64=~ll_min64;
ll ll_min32=1LL<<31;
ll ll_max32=~ll_min32;

ll MOD = 1000000007;

/*displaying functions for debug*/
template<class T> void show2(const T &x){cout << x;}
template<class T1,class T2> void show2(const pair<T1,T2> &x){
  cout << "{" << show2(x.first) << "," << show2(x.second) << "}";
}
template<class T> void show(const T &x){
  if (!IS_TEST) return;
  show2(x); cout <<endl;
}
template<class T> void v_show(const T &v, ll n=-1){
  if (!IS_TEST) return;
  auto itr=v.begin(); ll m=n;
  while(itr!=v.end() && m!=0 ){ show2(*itr); cout << " "; itr++; m--;}
  cout << endl;
}
template<class T> void vv_show(const T &v, ll n=-1){
  if (!IS_TEST) return;
  cout << "--------------------------------\n";
  auto itr=v.begin(); ll m=n;
  while(itr!=v.end() && m!=0 ){ v_show(*itr,n); itr++; m--;}
  cout << "--------------------------------" << endl;
}
/*--------------------------------*/

/*loading integers*/
void load(ll& x1){ cin >> x1; }
void load(ll& x1,ll& x2){ cin >> x1 >> x2; }
void load(ll& x1,ll& x2,ll& x3){ cin >> x1 >> x2 >> x3; }
void load(ll& x1,ll& x2,ll& x3,ll& x4){ cin >> x1 >> x2 >> x3 >> x4; }
void v_load(ll n, v_ll& v1, ll head=0, ll tail=0, ll init=0){
    ll m=n+head+tail; v1.assign(m,init);
    for (ll i=0;i<n;i++){ cin >> v1[i+head]; }
}
void v_load(ll n, v_ll& v1 ,v_ll& v2, ll head=0, ll tail=0, ll init=0){
    ll m=n+head+tail; v1.assign(m,init); v2.assign(m,init);
    for (ll i=0;i<n;i++){ cin >> v1[i+head] >> v2[i+head]; }
}
void v_load(ll n, v_ll& v1 ,v_ll& v2, v_ll& v3, ll head=0, ll tail=0, ll init=0){
    ll m=n+head+tail; v1.assign(m,init); v2.assign(m,init); v3.assign(m,init);
    for (ll i=0;i<n;i++){ cin >> v1[i+head] >> v2[i+head] >> v3[i+head]; }
}
void v_load(ll n, v_ll& v1 ,v_ll& v2, v_ll& v3, v_ll& v4, ll head=0, ll tail=0, ll init=0){
    ll m=n+head+tail; v1.assign(m,init); v2.assign(m,init); v3.assign(m,init); v4.assign(m,init);
    for (ll i=0;i<n;i++){ cin >> v1[i+head] >> v2[i+head] >> v3[i+head] >> v4[i+head]; }
}
/*--------------------------------*/

v_ll local_sort(ll x1=ll_max64, ll x2=ll_max64, ll x3=ll_max64, ll x4=ll_max64){
    v_ll x{x1,x2,x3,x4};
    sort(x.begin(),x.end());
    return x;
}

ll max(ll x,ll y){return x>y?x:y;}
ll max(v_ll::iterator b,v_ll::iterator e){
    ll ans=*b;
    while (b<e) {ans=max(ans,*b);b++;}
    return ans;
}
ll argmax(v_ll::iterator b,v_ll::iterator e){
    ll ans=0, cnt=0, val=*b;
    while (b<e) { if (val<*b) {ans=cnt; val=*b;} cnt++; b++;}
    return ans;
}

ll min(ll x,ll y){return x<y?x:y;}
ll min(v_ll::iterator b,v_ll::iterator e){
    ll ans=*b;
    while (b<e) {ans=min(ans,*b);b++;}
    return ans;
}
ll argmin(v_ll::iterator b,v_ll::iterator e){
    ll ans=0, cnt=0, val=*b;
    while (b<e) { if (val>*b) {ans=cnt; val=*b;} cnt++; b++;}
    return ans;
}

ll sum(v_ll::iterator b,v_ll::iterator e){
    ll ans=0;
    while (b<e) {ans+=*b;b++;}
    return ans;
}

template<class T> bool chmax(T& x,const T& y){ if (x>=y) return false; x=y; return true;}
template<class T> bool chmin(T& x,const T& y){ if (x<=y) return false; x=y; return true;}

template<class T> void quit(T x){cout << x << endl; exit(0);}
void yesno(bool x){cout << (x?"Yes":"No")<<endl;}

ll roundup(ll x,ll y){return (x-1)/y+1;}

ll rem(ll x,ll y){ ll z=x%y; return z>=0?z:z+y; }

//setprecision(digit)
//sort(##.begin(),##.end(),[&](auto &x, auto &y){if (x<y) return true;})
ll gcd(ll x,ll y){
    if (x<0)x=-x;
    if (y<0)y=-y;
    while (y>0){
        x%=y;swap(x,y);
    }
    return x;
}

ll N,M,K,H,W,Q,X,D,ans=0;
v_ll A,B,C,P;
int main(){
    load(N,X,D);
    vector<ll> A(N+1,0),B(N+1,0);
    for (ll i=1;i<=N;i++){
        A[i]=A[i-1]+i-1;
        B[i]=B[i-1]+N-i;
    }
    ll G;
    if (X==0&&D==0){
        quit(1);
    }
    if (D==0){
        quit(N+1);
    }
    if (X!=0&&D!=0)G=abs(D)/gcd(X,D);
    if (X==0)G=1;
    ll ans=0;
    ll up = X*G/D;
    for (ll i=0;i<=N;i++){
        A[i]+=i/G*up;
        B[i]+=i/G*up;
    }
    //TEST;
    v_show(A);
    v_show(B);
    for (ll i=0;(i<G&&i<=N);i++){
        multimap<ll,ll> M;
        for (ll j=i;j<=N;j+=G){
            M.insert(p_ll(A[j],1));
            M.insert(p_ll(B[j]+1,-1));
        }
        auto itr=M.begin();
        ll now=0,lev=0;
        while (itr!=M.end()){
            if (lev==0)now=(*itr).fi;
            lev+=(*itr).se;
            if (lev==0)ans+=(*itr).fi-now;
            ++itr;
        }
    }
    //cout << G << endl;
    cout << ans << endl;
}




Measured memory_bytes: 28416