#include <bits/stdc++.h>
#define ent '\n'
#define f first
#define s second
typedef long long ll;
using namespace std;
const int maxn = 2e5+12;
int mxs[maxn*4];
int mxt[maxn*4];
int ps[maxn*4];
int pt[maxn*4];
int s[maxn];
int t[maxn];
int p[maxn];
int n;
void upd(int v, int tl, int tr, int pos, int x, int y){
if(tl == tr){
ps[v] = pt[v] = tl;
mxs[v] = x;
mxt[v] = y;
}
else{
int mid = tl + tr >> 1;
if(pos <= mid){
upd(v*2, tl, mid, pos, x, y);
}
else{
upd(v*2+1, mid+1, tr, pos, x, y);
}
mxs[v] = max(mxs[v*2], mxs[v*2+1]);
mxt[v] = max(mxt[v*2], mxt[v*2+1]);
ps[v] = ps[v*2], pt[v] = pt[v*2];
if(mxs[v] == mxs[v*2+1]){
ps[v] = ps[v*2+1];
}
if(mxt[v] == mxt[v*2+1]){
pt[v] = pt[v*2+1];
}
}
}
pair<int, int> get(int v, int tl, int tr, int l, int r, int t){
if(tl > r || l > tr){
return {0, 0};
}
if(tl >= l && tr <= r){
if(t) return {mxt[v], pt[v]};
return {mxs[v], ps[v]};
}
int mid = tl + tr >> 1;
return max(get(v*2, tl, mid, l, r, t), get(v*2+1, mid+1, tr, l, r, t));
}
long long plan_roller_coaster(vector<int> S, vector<int> T){
n = S.size();
for(int i=0;i<n;i++){
p[i] = i;
s[i] = S[i], t[i] = T[i];
}
sort(p, p+n, [](int i, int j){
return t[i] < t[j];
});
sort(t, t+n);
for(int i=0;i<n;i++){
s[i] = S[p[i]];
}
for(int i=1;i<=n;i++){
upd(1, 1, n, i, s[i-1], t[i-1]);
}
int val = 2e9;
for(int it=0;it<n;it++){
int pos = 0;
for(int l=1, r=n; l<=r;){
int mid = l + r >> 1;
if(t[mid-1] <= val){
pos = mid;
l = mid + 1;
}
else r = mid - 1;
}
auto x = get(1, 1, n, 1, pos, 0), y = get(1, 1, n, 1, pos, 1);
if(x.s == 0){
return 1;
}
if(x.f < y.f){
val = get(1, 1, n, y.s, y.s, 0).f;
upd(1, 1, n, y.s, 0, 0);
}
else{
val = x.f;
upd(1, 1, n, x.s, 0, 0);
}
}
return 0;
}
