1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
#include<bits/stdc++.h>
#define ST first
#define ND second
#define ll long long
#define ld long double
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
using namespace std;

const ll  INF = 1e9 + 9;
const ll  MOD = 1e9 + 7;
const long long LINF = (ll)1e18 + 3;

// secik.insert({x, t++});
// secik.erase(secik.lower_bound({x,-1}));
// *secik.find_by_order(x)).first << "\n";
// secik.order_of_key(x)

//random_device device;
//mt19937 gener(device());
//uniform_int_distribution<ll > gen(0,n-1);
//gen(gener); // generate random number

const int SIZE = 5e5 + 5;

int main(){
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	
	int n; cin >> n;
	vector<pair<int,int> > miny(n);
	for(int i = 0; i < n; i++) cin >> miny[i].ST >> miny[i].ND;
	unordered_set<int> seciik;
	for(int i = 0; i < (1 << n); i++){
		multiset<pair<int,int> > secior;
		queue<pair<int,int> > st;
		for(int j = 0; j < n; j++){
			if(i & (1 << j)){
				st.push(miny[j]);
			} else {
				secior.insert(miny[j]);
			}
		}
		while(!st.empty()){
			auto it = st.front();
			if(secior.count(it)) secior.erase(secior.find(it));
			st.pop();
			auto iter = secior.lower_bound({it.ST - it.ND,-1e9});
			while(iter != secior.end() && (*iter).ST <= it.ST + it.ND){
				st.push(*iter);
				iter++;
			}
		}
		int maska = 0;
		for(int j = 0; j < n; j++){
			if(!secior.count(miny[j])) maska |= (1 << j);
		}
		seciik.insert(maska);
	}
	cout << seciik.size() << "\n";
	return 0;
}