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//#pragma GCC optimize("O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
using namespace std;
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //
namespace debug {
template <class c> struct rge { c b, e; }; template <class c> rge<c> range(c i, c j) { return rge<c>{i, j}; }
template <class c> char elo(...); template <class c> auto elo(c* a) -> decltype(cerr << *a, 0);
struct stream { ~stream() { cerr << endl; }
template <class c> typename enable_if <sizeof elo<c>(0) != 1, stream&>::type operator<<(c i) { cerr << boolalpha << i; return *this; }
template <class c> typename enable_if <sizeof elo<c>(0) == 1, stream&>::type operator<<(c i) { return *this << range(begin(i), end(i)); }
template <class a, class b> stream& operator<<(pair <a,b> p) { return *this << "(" << p.first << ", " << p.second << ")"; }
template <class c> stream& operator<<(rge<c> d) { *this << "["; for (auto it=d.b; it!=d.e; it++) *this << ", " + 2 * (it == d.b) << *it; return *this << "]"; }
stream& _dbg(const string& s, int i, int b) {} template <class c, class ... cs> stream& _dbg(const string& s, int i, int b, c arg, cs ... args) {
if (i == s.size()) return (*this << ": " << arg << ""); b += (s[i] == '(') + (s[i] == '[') + (s[i] == '{'); b -= (s[i] == ')') + (s[i] == ']') + (s[i] == '}');
if (s[i] == ',' && b == 0) return (*this << ": " << arg << "     ")._dbg(s, i+1, b, args...); return (s[i] == ' ' ? *this : *this << s[i])._dbg(s, i+1, b, arg, args...); } };}
#define dout debug::stream()
#define dbg(...) ((dout << ">> ")._dbg(#__VA_ARGS__, 0, 0, __VA_ARGS__))
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //
#define f first
#define s second
#define sc scanf
#define pr printf
#define mp make_pair
#define pb push_back
#define all(x) x.begin(),x.end()
#define ss(x) ((int)((x).size()))
#define rep(i, a, b) for(int (i)=(a);i<=(b);(i)++)
#define per(i, a, b) for(int (i)=(b);i>=(a);(i)--)
#define lowb(v, x) (lower_bound(all(v),(x))-(v).begin())
#define uppb(v, x) (upper_bound(all(v),(x))-(v).begin())
#define upgrade ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define erase_duplicates(x) {sort(all(x));(x).resize(distance((x).begin(), unique(all(x))));}
template <class p, class q> pair<p,q> operator-(pair<p,q> a, pair<p,q> b) { return mp(a.f-b.f, a.s-b.s); }
template <class p, class q> pair<p,q> operator+(pair<p,q> a, pair<p,q> b) { return mp(a.f+b.f, a.s+b.s); }
template <class p, class q> void umin(p& a, const q& b) { if (a > b) a = b; }
template <class p, class q> void umax(p& a, const q& b) { if (a < b) a = b; }
using lf=long double;
using ll=long long;
using cll=const ll;
using cint=const int;
using pll=pair<ll,ll>;
using pii=pair<int,int>;
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //

const ll inf = 1000000000000000005;
const int mod = 1000000007;
const int N = 500005;
const int K = 19;
int n, i, j;
ll pos [N];
int dp [N];
int pre [N];
ll range [N];
int tree [N];
int Rank [N];
ll R [N][K];
ll L [N][K]; 
vector <int> vec [N];

inline int sum (cint& a, cint& b)
	{
	if (a + b >= mod) return a + b - mod;
	if (a + b < 0) return a + b + mod;
	return a + b;
	}

inline ll MIN (cint& a, cint& b)
	{
	if (a >= b) return inf;
	int k = Rank[b - a];
	return min(L[a][k], L[b - (1 << k)][k]);
	}

inline ll MAX (cint& a, cint& b)
	{
	if (a >= b) return -inf;
	int k = Rank[b - a];
	return max(R[a][k], R[b - (1 << k)][k]);
	}

inline void update (int u, cint& val)
	{
	for (u++; u<N; u+=(u&-u))
		tree[u] = sum(tree[u], val);
	}

inline int query (int u)
	{
	int res = 0;
	for (u++; u>0; u-=(u&-u))
		res = sum(res, tree[u]);
	return res;
	}

inline int query (cint& a, cint& b) {
	return sum(query(b), -query(a - 1));
	}

int main()
	{
	scanf("%d", &n);

	for (i=1; i<=n; i++)
		{
		scanf("%lld%lld", &pos[i], &range[i]);
		R[i][0] = pos[i] + range[i];
		L[i][0] = pos[i] - range[i];
		}
	
	Rank[1] = 0;
	for (i=2; i<N; i++)
		Rank[i] = Rank[i/2] + 1;

	for (j=0; j+1 < K; j++)
		for (i=1; i + (1 << j) <= n; i++)
			{
			R[i][j+1] = max(R[i][j], R[i + (1 << j)][j]);
			L[i][j+1] = min(L[i][j], L[i + (1 << j)][j]);
			}

	dp[0] = 0;
	pre[0] = 1;
	update(0, pre[0]);
	pos[n + 1] = inf + inf + inf;

	for (i=1; i<=n; i++)
		{
		for (int a : vec[i])
			update(a, -pre[a]);

		int a, b;

		a = 0;
		b = i + 1;
		while (b - a > 1)
			(MAX((a + b) / 2, i + 1) >= pos[i + 1] ? a : b) = (a + b) / 2;

		dp[i] = query(a, i);
		
		pre[i] = sum(pre[i-1], dp[i-1]);
		update(i, pre[i]);
		
		a = i;
		b = n + 1;
		while (b - a > 1)
			(MIN(i + 1, (a + b) / 2 + 1) <= pos[i] ? b : a) = (a + b) / 2;
		
		vec[b].pb(i);
		}

	int out = sum(dp[n], pre[n]);

	printf("%d\n", out);
	
	return 0;
	}