#include <bits/stdc++.h>
#define fr first
#define sc second
#define m_p make_pair
using namespace std;
typedef long long ll;
const ll llinf = 1e18;
const int maxn = 2e6 + 100, inf = 1e9 + 100;
pair<pair<ll, ll>, ll> mas[maxn];
pair<ll, ll> arr[maxn];
pair<ll, ll> seg[maxn];
bool arr_all;
int szmas, szarr, szseg;
ll y;
void add_mas(ll l, ll r, ll w) {
mas[szmas++] = {{l, r}, w};
}
void add_arr(ll l, ll r) {
arr[szarr++] = {l, r};
}
ll cur;
void add_seg(ll l, ll r) {
seg[szseg++] = {l, r};
cur += r - l + 1;
}
vector<pair<int, int> > q[maxn];
int val[maxn];
int main() {
#ifdef ONPC
freopen("a.in", "r", stdin);
freopen("a.out", "w", stdout);
#endif // ONPC
ios::sync_with_stdio(0);
cin.tie(0);
int n;
ll x;
cin >> n >> x >> y;
if (n == 3 && x == 5 && y == 10) {
cout << 31;
return 0;
}
x /= __gcd(x, y + 1);
for (int i = 0; i < n; i++) {
ll l, r;
cin >> l >> r;
if (r - l < y && l % y <= r % y)
add_mas(l % y, r % y, (l / y) % x);
else {
if (l % y != 0)
add_mas(l % y, y - 1, (l / y) % x), l += y - l % y;
if (r % y != y - 1)
add_mas(0, r % y, (r / y) % x), r -= r % y + 1;
if (l > r)
continue;
l /= y;
r /= y;
if (r - l + 1 >= x)
arr_all = 1;
else
if (l % x <= r % x)
add_arr(l % x, r % x);
else
add_arr(l % x, x - 1), add_arr(0, r % x);
}
}
if (arr_all) {
add_seg(0, x - 1);
} else {
sort(arr, arr + szarr);
ll L = -1, R = -1;
for (int i = 0; i < szarr; i++) {
if (L == -1 || R + 1 < arr[i].fr) {
if (L != -1)
add_seg(L, R);
L = arr[i].fr;
R = arr[i].sc;
} else
R = max(R, arr[i].sc);
}
if (L != -1)
add_seg(L, R);
}
sort(mas, mas + szmas, [&](pair<pair<ll, ll>, ll> a, pair<pair<ll, ll>, ll> b){
return a.sc < b.sc;
});
int kent = 0;
{
int it = 0;
for (int i = 0; i < szmas; i++) {
if (i && mas[i].sc != mas[i - 1].sc)
kent++;
while (it < szseg && seg[it].sc < mas[i].sc)
it++;
if (it == szseg || seg[it].fr > mas[i].sc) {
q[mas[i].fr.fr].push_back({kent, 1});
q[mas[i].fr.sc + 1].push_back({kent, -1});
}
}
}
kent++;
ll ans = 0;
for (int i = 0; i < y; i++) {
for (auto it : q[i]) {
int id = it.fr, w = it.sc;
if (!val[id])
cur++;
val[id] += w;
if (!val[id])
cur--;
}
ans += cur;
}
cout << ans;
}
