#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC optimize("conserve-stack")
#include<bits/stdc++.h>
#define int long long
#define ll long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define NHP ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define mask(k) (1<<k)
#define mp make_pair
#define checktime cerr << (double)clock() / CLOCKS_PER_SEC * 1000 << " ms";
using namespace std;
#define getchar_unlocked getchar
inline int scan()
{
char c = getchar_unlocked();
int x = 0;
while (c < '0' || c > '9')
{
c = getchar_unlocked();
}
while (c >= '0' && c <= '9')
{
x = (x << 1) + (x << 3) + c - '0';
c = getchar_unlocked();
}
return x;
}
void phongbeo();
const int inf = 2e9;
const ll mod2 = 1e9 + 7;
const int mod1 = 998244353;
const ll base=67;
int dx[4] = {1, -1, 0, 0};
int dy[4] = {0, 0, 1, -1};
int add(int x,int y)
{
if(x+y>=mod2) x-=mod2;
if(x+y<0)x+=mod2;
return x+y;
}
struct icd
{
long double a;
int b;
};
struct ib
{
int a;
int b;
};
struct ic
{
int a, b, c;
};
struct id
{
int a, b, c, d;
};
struct ie
{
int a, b, c, d, e;
};
int n, m, s1, s2, s4, s3, sf, k, s5, s6, mx, s7, s8, s9, mx2, res, dem2 = 0, dem = 0, s33, dem3, dem4, mid, l2, r2, center;
int i, s10, s12,k1,k2,k3,s11,lim,w,l,r ;
int kk;
int el = 19;
main()
{
if(fopen(task".inp","r"))
{
fin(task);
fou(task);
}
NHP
/// cin>>s1;
// modwwe
phongbeo();
// checktime
}
bool cmp(ic a,ic b)
{
return a.b<b.b;
}
bool cmp2(ib a,ib b)
{
return a.a>b.a;
}
vector<ib> t[800001];
ic a[200001];
vector<ib> v;
int pos[200001];
void upd(int node,int l,int r,int l1,ib x)
{
while(!t[node].empty()&&t[node].back().b>x.b) t[node].pop_back();
t[node].pb(x);
if(l==r) return;
int mid=l+r>>1;
if(l1<=mid)upd(node<<1,l,mid,l1,x);
else upd(node<<1|1,mid+1,r,l1,x);
}
void get(int node,int l,int r,int l1,int r1)
{
if(l>r1||r<l1) return;
if(l>=l1&&r<=r1)
{
l=1;
r=t[node].size();
k=t[node].size();
while(l<=r)
{
int mid=l+r>>1;
if(t[node][k-mid].a>=s5)r=mid-1;
else l=mid+1;
}
s4=s4+r;
if(!t[node].empty())
s5=min(s5,t[node].back().a);
return;
}
int mid=l+r>>1;
get(node<<1,l,mid,l1,r1);
get(node<<1|1,mid+1,r,l1,r1);
}
void phongbeo()
{
cin>>n;
for(int i=1; i<=n; i++)
cin>>a[i].a>>a[i].b,a[i].c=i,v.pb({a[i].a,a[i].c});
sort(a+1,a+1+n,cmp);
for(int i=1; i<=n; i++) pos[a[i].c]=i;
sort(v.begin(),v.end(),cmp2);
for(auto [x,y]:v)
{
y=pos[y];
s5=inf;
get(1,1,n,y,n);
upd(1,1,n,y, {x,y});
/// chen cai be nhat vao => con nao nam ben phai se ko dc dung nx
}
cout<<s4;
}
