///huynhocute123///
#include<bits/stdc++.h>
using namespace std;
#define S second
#define F first
#define pii pair<int,int>
#define piii pair<int,pair<int,int>>
#define pb push_back
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = b; i >= a; --i)
#define ALL(v) v.begin(),v.end()
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
//random_device rd;
//mt19937 rng(rd());
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
//#define int long long
const int MAX = 1e9+9;
const long long MAXLL = 1e18+9;
const double pi = 3.14159265358979323846;
const double rad = 3.14159265358979323846 /180;
bool minimize(int &u, int v){
if(v < u){
u = v;
return 1;
}
return 0;
}
bool maximize(int &u, int v){
if(v > u){
u = v;
return 1;
}
return 0;
}
bool maximizell(long long &u, long long v){
if(v > u){
u = v;
return 1;
}
return 0;
}
bool minimizell(long long &u, long long v){
if(v < u){
u = v;
return 1;
}
return 0;
}
const int mod = 1e9 + 7;
inline int fastPow(int a, int n){
if(n == 0) return 1;
int t = fastPow(a, n >> 1);
t = 1ll * t * t % mod;
if(n & 1) t = 1ll * t * a % mod;
return t;
}
const int maxN = 1e6 + 999 ;
struct Geo{
long long x ,y;
Geo(){};
Geo(long long _x ,long long _y){
x = _x;
y = _y;
}
void read(){
cin >> x >> y;
}
};
struct Line{
long long A ,B ,C;
Line(long long _A ,long long _B ,long long _C){
A = _A;
B = _B;
C = _C;
}
};
Line build(const Geo& A ,const Geo& B){
Geo vec = Geo(B.x - A.x , B.y - A.y);
Geo Nvec = Geo(vec.y ,-vec.x);
return Line(Nvec.x , Nvec.y , -(1LL * Nvec.x * A.x + 1LL * Nvec.y * A.y));
}
Geo heh[maxN];
int ccw(const Geo& A ,const Geo& B ,const Geo&C){
long long X = 1LL * (C.x - A.x) * (B.y - A.y) - 1LL*(B.x - A.x) * (C.y - A.y);
if(X == 0)return 0;
return( X > 0 ? 1 : -1);
}
int n, h;
double kaka(const Geo& A ,const Geo& B){
Line AB = build(A ,B);
// cout << AB.A << " "<< AB.B << " "<< AB.C << '\n';
if(AB.A == 0)return -MAXLL;
return (1.0 * (-AB.B * h - AB.C))/ (1.0 * AB.A);
}
int L[maxN] , R[maxN];
inline void solve(){
cin >> n >> h;
FOR(i, 1, n)heh[i].read();
vector<int>stk;
FOR(i, 2, n){
while(stk.size() >= 2 && ccw(heh[stk[stk.size() - 2]], heh[stk.back()], heh[i]) <= 0){
// cout << stk[stk.size() - 2] << " "<< stk.back() << " "<< i << '\n';
stk.pop_back();
}
if(stk.size())L[i] = stk.back();
else L[i] = i - 1;
if( (i % 2) == 0 )stk.pb(i);
}
stk.clear();
REP(i, 1, n){
while(stk.size() >= 2 && ccw(heh[i], heh[stk.back()], heh[stk[stk.size() - 2]]) <= 0){
// cout << i << " "<< stk.back() << " "<< stk[stk.size() - 2] << '\n';
stk.pop_back();
}
if(stk.size())R[i] = stk.back();
else R[i] = i + 1;
if( (i % 2) == 0 )stk.pb(i);
}
// for(int i = 3; i <= n - 2 ;i += 2){
// cout << i << " " << L[i] << '\n';
// }
int ans = 0;
vector<pair<double ,double>>huh;
for(int i = 3; i <= n - 2;i += 2)huh.pb({ kaka(heh[i] , heh[L[i]]) , kaka(heh[i] , heh[R[i]]) });
sort(ALL(huh));
for(int i = 0 ; i < huh.size();){
int j = i;
double mx = huh[i].S;
while(j < huh.size()){
if(huh[j].F > mx)break;
mx = min(mx , huh[j].S);
++j;
}
i = j;
++ans;
}
cout << ans;
// for(int i = 3; i <= n ; i += 2)cout << R[i] << '\n';
// Geo A(-4 ,3);
// Geo B(0 ,4 );
// Geo C(2 ,2);
// cout << ccw(A ,B ,C);
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
#define NAME "task"
if(fopen(NAME".inp", "r")){
freopen(NAME".inp", "r" ,stdin);
// freopen(NAME".out", "w" ,stdout);
}
int tc = 1;
// cin >> tc;
while( tc-- )solve();
cerr << '\n' << "Time elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << " s\n" ;
}
