#include <bits/stdc++.h>
#define int long long
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
using namespace std;
const int N = 1e6+5;
const double EPS = 1e-7;
pair<double,double> seg[N];
int st[N], id[N];
int n, h;
double findp(int x1, int y1, int x2, int y2){
assert(y1!=y2);
return 1.0*(h-y1)*(x2-x1)/(y2-y1)+x1;
}
bool check(pair<double,double> a, pair<double,double> b, pair<double,double> c){
return (b.second-a.second)*(c.first-a.first) <= (c.second-a.second)*(b.first-a.first);
}
signed main(){
fastio
//freopen("input.in","r",stdin);
cin >> n >> h;
vector<pair<double,double>> v(1);
for(int i = 1;i <= n;i++){
int x,y;
cin >> x >> y;
v.push_back({x,y});
}
vector<int> st;
for (int i = 1; i <= n; i++) {
//dy/dx < dy<dx => (v[st.top()].second-v[i].second)
while(st.size() > 2&&!check(v[i],v[st[st.size()-1]],v[st[st.size()-2]])) st.pop_back();
if(i%2==1&&!st.empty()) seg[i].first = findp(v[i].first,v[i].second, v[st.back()].first, v[st.back()].second);
st.push_back(i);
}
st.clear();
for(int i = n; i >= 1; i--) {
while(st.size() > 2&&check(v[i],v[st[st.size()-1]],v[st[st.size()-2]])) st.pop_back();
if(i%2==1&&!st.empty()) seg[i].second = findp(v[i].first,v[i].second, v[st.back()].first, v[st.back()].second);
st.push_back(i);
}
for(int i = 3;i <= n;i++){
id[i/2] = i;
}
sort(id+1,id+n/2,[&](int a, int b){
return seg[a].second < seg[b].second;
});
double tmp = seg[id[1]].second;
int ans = 1;
for (int i = 1; i <= n / 2 - 1; ++i) {
if (tmp >= seg[id[i]].first)
continue;
//cout << seg[i].first << " " << seg[i].second << "\n";
tmp = seg[id[i]].second;
++ans;
}
cout << ans << "\n";
}
