#include <bits/stdc++.h>
using namespace std;
#define print(l) for(auto i:l) cout<<i<<" ";cout<<endl;
#define input(t,l,n) vector<t>l(n);for(int i = 0;i<n;i++)cin>>l[i];
#define int long long
#define pb push_back
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define all(l) l.begin(),l.end()
#define pii pair<int,int>
#define fi first
#define se second
const int M = 1e9+7;
const int inf = 1e18;
void io(){
#ifndef ONLINE_JUDGE
freopen("input.txt","r",stdin);
// freopen("outputf.in","w",stdout);
#endif
}
int bp(int x, int y, int p){
int res = 1;
x = x % p;
while (y > 0) {
if (y & 1)
res = (res * x) % p;
y = y >> 1;
x = (x * x) % p;
}
return res;
}
int MI(int n, int p){
return bp(n, p - 2, p);
}
int mul(int x,int y, int p){
return x * 1ull * y % p;
}
int di(int x,int y, int p){
return mul(x, MI(y, p), p);
}
map<int , vector<int>>adj;
map<int,int>give;
int n , m , k , q;
map<int,int>po;
void solve(int testcase_number){
cin>>n;
vector<pii>inp;
for(int i = 0;i<n;i++){
cin>>m>>k;
po[m] = max(po[m],k);
// inp.pb({m,k});
}
for(auto i:po){
inp.pb(i);
// cout<<i.fi<<" "<<i.se<<endl;
}
n = inp.size();
int ans = n ;
if(n>16){
cout<<ans<<endl;
return;
}
for(int i = 0;i<(1ll<<n);i++){
vector<int>got;
vector<int>vis(n+1,0);
int tc =0 ;
for(int j = 0;j<n;j++){
if(i&(1ll<<j)){
got.pb(j);
vis[j] = 1;
tc++;
}
}
for(int j:got){
for(int k = 0;k<n;k++){
if(!vis[k] and abs(inp[j].fi-inp[k].fi) <= inp[j].se-inp[k].se){
vis[k] = 1;
tc++;
}
}
}
if(tc == n){
ans = min(ans,(int)got.size());
}
}
cout<<ans<<endl;
}
signed main(){
// io();
ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
cin.tie(0), cout.tie(0);
cout << fixed<<setprecision(9);
int t = 1;
// cin>>t;
for(int i = 1;i<=t;i++){
solve(i);
}
}
