#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;
typedef long long ll;
typedef pair<ll, ll> ii;
typedef pair<ii, ii> i4;
int n;
ll h;
ii p[1000005];
int Lid[1000005], Rid[1000005];
int ord[1000005];
ll cross(ii x, ii y){
return x.fi*y.se - x.se*y.fi;
}
bool ccw(int a, int b, int c){
if (a == -1) return (p[b].se <= p[c].se);
ii x = ii(p[b].fi - p[a].fi, p[b].se - p[a].se);
ii y = ii(p[c].fi - p[b].fi, p[c].se - p[b].se);
return cross(x,y) > 0ll;
}
bool cw(int a, int b, int c){
if (a == -1) return (p[b].se <= p[c].se);
ii x = ii(p[b].fi - p[a].fi, p[b].se - p[a].se);
ii y = ii(p[c].fi - p[b].fi, p[c].se - p[b].se);
return cross(x,y) < 0ll;
}
ii extrapolate(int a, int b){
ll dy = p[b].se - p[a].se;
ll dx = p[b].fi - p[a].fi;
return ii(p[a].fi*dy + (h-p[a].se)*dx, dy);
}
bool cmp(ii a, ii b){
//printf("comparing (%lld,%lld) and (%lld,%lld)\n",a.fi,a.se,b.fi,b.se);
return a.fi*b.se < b.fi*a.se;
}
bool cmp3(ii a, ii b){
//printf("comparing (%lld,%lld) and (%lld,%lld)\n",a.fi,a.se,b.fi,b.se);
return a.fi*b.se > b.fi*a.se;
}
bool cmp2(i4 a, i4 b){
return cmp(a.se, b.se);
}
vector<pair<ii, ii> > v;
int main(){
scanf("%d%lld",&n,&h);
for (int i = 1; i <= n; i++){
scanf("%lld%lld",&p[i].fi,&p[i].se);
}
deque<int> dq;
dq.push_back(-1);
for (int i = 1; i <= n; i++){
while (dq.size() >= 2 && ccw(dq[dq.size()-2], dq[dq.size()-1], i)){
dq.pop_back();
}
Lid[i] = dq.back();
dq.push_back(i);
}
dq.clear();
dq.push_back(-1);
for (int i = n; i >= 1; i--){
while (dq.size() >= 2 && cw(dq[dq.size()-2], dq[dq.size()-1], i)){
dq.pop_back();
}
Rid[i] = dq.back();
dq.push_back(i);
}
for (int i = 3; i < n; i+=2){
//printf("point %d goes to %d, %d\n",i,Lid[i],Rid[i]);
ii L = extrapolate(i,Lid[i]);
ii R = extrapolate(i,Rid[i]);
v.push_back({L,R});
//printf("%lld %lld, %lld %lld\n",L[i].fi,L[i].se, R[i].fi, R[i].se);
}
sort(v.begin(), v.end(), cmp2);
ii last = v[0].se;
int ct = 1;
for (auto x : v){
//printf("%lld %lld vs %lld %lld\n",x.fi.fi,x.fi.se, last.fi, last.se);
if (cmp3(x.fi, last)){
//printf("setting new R\n");
last = x.se;
ct++;
}
}
printf("%d",ct);
}
