#define fast ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#include <bits/stdc++.h>
using namespace std;
#define sqr 200
#define mid (l+r)/2
#define pb push_back
#define ppb pop_back
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define ins insert
#define era erase
#define C continue
#define mem(dp,i) memset(dp,i,sizeof(dp))
#define mset multiset
typedef long long ll;
typedef short int si;
typedef long double ld;
typedef pair<int,int> pi;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pi> vpi;
typedef vector<pll> vpll;
const ll mod=1e9+7;
const ll inf= 4e18;
const ld pai=acos(-1);
#include "railroad.h"
ll n ;
pll a[200009];
ll tree[800009];
void build(int node,int l,int r){
if ( l==r ){
tree[node]=a[l].se;
return ;
}
build(node*2,l,mid);
build(node*2+1,mid+1,r);
tree[node]=min(tree[node*2],tree[node*2+1]);
}
void upd(int node,int l,int r,int id){
if ( l==r ){
tree[node]=inf;
return ;
}
if ( id<=mid) upd(node*2,l,mid,id);
else upd(node*2+1,mid+1,r,id);
tree[node]=min(tree[node*2],tree[node*2+1]);
}
ll query(int node,int l,int r,int s,int e ){
if ( s>r || e<l ) return inf;
if ( s<=l && e>=r) return tree[node];
return min(query(node*2,l,mid,s,e) , query(node*2+1,mid+1,r,s,e) );
}
int bin(ll x){
int l =-1,r=n;
while ( r-l>1){
if ( a[mid].fi<=x)l=mid;
else r=mid;
}
return l;
}
long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
n = (int) s.size();
for(int i =0 ;i < n;i ++ ) {
a[i]={s[i],t[i]};
}
sort(a,a+n);
reverse(a,a+n);
build(1,0,n-1);
int N = n ;
int S =1 ;
while ( N -- ) {
int l =0 ,r=bin(S);
if ( r == -1 ) return 1 ;
int X = query (1,0,n-1,l,r);
if ( X == inf ) return 1;
l--,r++;
while ( r-l >1 ){
if ( query(1,0,n-1,0,mid) == X ) r=mid;
else l=mid;
}
S = X ;
upd(1,0,n-1,r);
}
return 0 ;
}
