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#include <iostream>
#include <vector>
#include <queue>
using namespace std;

struct Circle {
	unsigned long long a;
	unsigned long long r;
	
	Circle (unsigned long long a0, unsigned long long r0) {
		a = a0;
		r = r0;
	}
};

vector<Circle> circles;
vector<unsigned long long> solutionsWith;
vector<unsigned long long> solutionsWithout;
const unsigned long long p = 1000000007;
vector<int> nearestLeftReaching;
vector<vector<int>> reachingTmp;
priority_queue<int> lefts;

int binSearch(int start, int end, unsigned long long val) {
	if (start == end) {
		return start;
	}
	
	int mid = (start + end + 1) / 2;
	if (circles[mid].a <= val) {
		return binSearch(mid, end, val);
	} else {
		return binSearch(start, mid - 1, val);
	}
}

void calculateNearestLeftReaching() {
	reachingTmp.resize(circles.size());
	
	for (unsigned i = 0; i < circles.size(); ++i) {
		unsigned j = binSearch(i, circles.size() - 1, circles[i].a + circles[i].r);
		if (j > i) {
			reachingTmp[j].push_back(i);
		}
	}

	for (int i = circles.size() - 1; i >= 0; --i) {
		while (!reachingTmp[i].empty()) {
			lefts.push(reachingTmp[i].back());
			reachingTmp[i].pop_back();
		}
		if (!lefts.empty() && lefts.top() == i) {
			lefts.pop();
		}
		
		if (lefts.empty()) {
			nearestLeftReaching[i] = -1;
		} else {
			nearestLeftReaching[i] = lefts.top();
		}
	}	
}

int getNearestLeftReachingBrute(int pos) {
	for (int i = pos - 1; i >= 0; --i) {
		if (circles[pos].a - circles[i].a <= circles[i].r) {
			return i;
		}
	}
	return -1;
}

int getNearestLeftReaching(int pos) {
	return nearestLeftReaching[pos];
}

int getFurthestLeft(int pos) {
	unsigned long long leftDist;
	
	if (circles[pos].a < circles[pos].r) {
		return -1;
	} else {
		leftDist = circles[pos].a - circles[pos].r;
	}
	
	for (int i = pos - 1; i >= 0; --i) {
		if (circles[i].a < leftDist) {
			return i;
		}
		
		if (circles[i].a < circles[i].r) {
			return -1;
		} else if (leftDist > circles[i].a - circles[i].r) {
			leftDist = circles[i].a - circles[i].r;
		}
	}
	
	return -1;
}

int main() {
	ios_base::sync_with_stdio(0);
	int n;
	unsigned long long a, r;
	
	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> a;
		cin >> r;
		circles.push_back(Circle(a, r));
		solutionsWith.push_back(0);
		solutionsWithout.push_back(0);
		nearestLeftReaching.push_back(-1);
	}
	
	calculateNearestLeftReaching();
	
	solutionsWith[0] = 1;
	solutionsWithout[0] = 1;
	
	for (int i = 1; i < n; ++i) {
		int j = getFurthestLeft(i);
		if (j < 0) {
			solutionsWith[i] = 1;
		} else {
			solutionsWith[i] = (solutionsWith[j] + solutionsWithout[j]) % p;
		}
		
		int k = getNearestLeftReaching(i);
		if (k < 0) {
			solutionsWithout[i] = (solutionsWith[i - 1] + solutionsWithout[i - 1]) % p;
		} else {
			solutionsWithout[i] = (p + solutionsWith[i - 1] + solutionsWithout[i - 1] - solutionsWith[k]) % p;
		}
	}
	
	cout << (solutionsWith[n - 1] + solutionsWithout[n - 1]) % p << endl;
	
/*	cout << endl << endl;
	for (int i = 0; i < n; ++i) {
		cout << getNearestLeftReaching(i) << " ";
	}
	cout << endl;*/
	
	return 0;
}