#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define int ll
#define nl '\n'
#define vt vector
#define ar array
#define ff first
#define ss second
#define all(x) x.begin(), x.end()
#define px cout << "YES\n"
#define py cout << "NO\n"
void _() {
int n; cin >> n;
vt<int> x(n), e(n);
for(int i = 0; i < n; i++) {
cin >> x[i] >> e[i];
}
int ans = n;
for(int msk = 0; msk < (1 << n); msk++) {
int ok = 0;
for(int i = 0; i < n; i++) {
if(((msk >> i) & 1) == 0) continue;
for(int j = 0; j < n; j++) {
if((msk >> j) & 1 || abs(x[i] - x[j]) <= e[i] - e[j]) {
ok |= (1 << j);
}
}
}
if(ok == (1 << n) - 1) {
int v = __builtin_popcountll(msk);
ans = min(ans, v);
}
}
cout << ans << nl;
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int tt = 1;
// cin >> tt;
while(tt--){_();}
}
