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#include <bits/stdc++.h>
using namespace std;

void __print(int x) { cerr << x; }
void __print(int64_t x) { cerr << x; }
void __print(uint32_t x) { cerr << x; }
void __print(uint64_t x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template<typename T, typename V>
void __print(const pair<T, V> &x) { cerr << '('; __print(x.first); cerr << ", "; __print(x.second); cerr << ')'; }
template<typename T>
void __print(const T &x) { int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}"; }
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) { __print(t); if (sizeof...(v)) cerr << ", "; _print(v...); }

#define debug(x...) cerr << " > [" << #x << "] = ["; _print(x)

const int64_t mod = 1e9 + 7;
const int64_t oo = 1e18 + 5;

map<int64_t, int> sc;

void init() {
    int sc_timer = 0;
    for(auto &p : sc) p.second = sc_timer++;
}

struct TreeNode {
    int64_t sum, lazy;
    TreeNode *leftNode, *rightNode;
    TreeNode() : sum(0), lazy(-1), leftNode(nullptr), rightNode(nullptr) {}
    TreeNode(int64_t _sum, int64_t _lazy) : sum(_sum), lazy(_lazy), leftNode(nullptr), rightNode(nullptr) {}
    TreeNode(TreeNode* _leftNode, TreeNode* _rightNode) : sum(0), lazy(-1), leftNode(_leftNode), rightNode(_rightNode) {}
    TreeNode(int64_t _sum, int64_t _lazy, TreeNode* _leftNode, TreeNode* _rightNode) : sum(_sum), lazy(_lazy), leftNode(_leftNode), rightNode(_rightNode) {}
};

TreeNode* build(int left, int right) {
    if(left == right) return new TreeNode();
    int mid = (left + right) / 2;
    return new TreeNode(build(left, mid), build(mid + 1, right));
}

void push(TreeNode* node, int left, int right) {
    if(node->lazy == -1) return;
    int64_t sz = (right - left + 1) / 2;
    if(node->leftNode == nullptr) {
        node->leftNode = new TreeNode((node->lazy * sz) % mod, node->lazy);
    }
    else {
        node->leftNode->sum = (node->lazy * sz) % mod;
        node->leftNode->lazy = node->lazy;
    }
    if(node->rightNode == nullptr) {
        node->rightNode = new TreeNode((node->lazy * sz) % mod, node->lazy);
    }
    else {
        node->rightNode->sum = (node->lazy * sz) % mod;
        node->rightNode->lazy = node->lazy;
    }
    node->lazy = -1;
}

int64_t read(TreeNode* node, int left, int right, int l, int r) {
    if(left > r or right < l) {
        return 0;
    }
    if(left >= l and right <= r) {
        return node->sum;
    }
    push(node, left, right);
    int mid = (left + right) / 2;
    return (read(node->leftNode, left, mid, l, r) + read(node->rightNode, mid + 1, right, l, r)) % mod;
}

TreeNode* change(TreeNode* node, int left, int right, int l, int r, int64_t val) {
    if(left > r or right < l) {
        return node;
    }
    if(left >= l and right <= r) {
        int64_t sz = (right - left + 1);
        return new TreeNode((val * sz) % mod, val);
    }
    push(node, left, right);
    int mid = (left + right) / 2;
    TreeNode* curleft = change(node->leftNode, left, mid, l, r, val);
    TreeNode* curright = change(node->rightNode, mid + 1, right, l, r, val);
    int64_t new_sum = (curleft->sum + curright->sum) % mod;
    return new TreeNode(new_sum, node->lazy, curleft, curright);
}

int n;
vector<int64_t> a;
vector<int64_t> r;
vector<int> left_id;
vector<int> right_id;
vector<int64_t> left_range;
vector<int64_t> right_range;
vector<int64_t> max_len;
vector<bool> processed;

void process(int l, int p) {
    if(l > p) return;
    int i = (l + p) / 2;
    if(processed[i]) return;
    processed[i] = true;
    int64_t max_left = a[i] - r[i];
    int64_t max_right = a[i] + r[i];
    left_id[i] = i - 1;
    right_id[i] = i + 1;
    while((left_id[i] > 0 and max_left <= a[left_id[i]]) or (right_id[i] < n and max_right >= a[right_id[i]])) {
        while(left_id[i] > 0 and max_left <= a[left_id[i]]) {
            if(processed[left_id[i]]) {
                max_left = min(max_left, left_range[left_id[i]]);
                max_right = max(max_right, right_range[left_id[i]]);
                right_id[i] = max(right_id[i], right_id[left_id[i]]);
                left_id[i] = left_id[left_id[i]];
            }
            else {
                max_left = min(max_left, a[left_id[i]] - r[left_id[i]]);
                max_right = max(max_right, a[left_id[i]] + r[left_id[i]]);
                left_id[i]--;
            }
        }
        while(right_id[i] < n and max_right >= a[right_id[i]]) {
            if(processed[right_id[i]]) {
                max_left = min(max_left, left_range[right_id[i]]);
                max_right = max(max_right, right_range[right_id[i]]);
                left_id[i] = min(left_id[i], left_id[right_id[i]]);
                right_id[i] = right_id[right_id[i]];
            }
            else {
                max_left = min(max_left, a[right_id[i]] - r[right_id[i]]);
                max_right = max(max_right, a[right_id[i]] + r[right_id[i]]);
                right_id[i]++;
            }
        }
    }
    left_range[i] = max_left;
    right_range[i] = max_right;
    process(l, i - 1);
    process(i + 1, p);
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);

    cin >> n;
    n++;
    a.resize(n + 1, oo);
    r.resize(n + 1);
    left_id.resize(n + 1);
    right_id.resize(n + 1);
    left_range.resize(n + 1);
    right_range.resize(n + 1);
    max_len.resize(n + 1);
    processed.resize(n + 1, false);
    processed[0] = true;
    a[0] = -oo;
    r[0] = 0;
    left_id[0] = -1;
    right_id[0] = 1;
    max_len[0] = 0;
    sc[0];
    for(int i = 1; i < n; i++) {
        cin >> a[i] >> r[i];
        a[i]++;
        sc[a[i]];
        sc[a[i] + r[i]];
        max_len[i] = max(max_len[i - 1], a[i] + r[i]);
    }
    process(1, n - 1);
    init();
    int BASE = 1;
    while(BASE <= (int)sc.size()) BASE <<= 1;
    vector<TreeNode*> state;
    TreeNode* root = build(0, BASE - 1);
    TreeNode* root2 = change(root, 0, BASE - 1, sc[0], sc[0], 1);

    state.push_back(root2);
    for(int i = 1; i < n; i++) {
        TreeNode* cur_root = state.back();
        TreeNode* temp_root = change(cur_root, 0, BASE - 1, sc[a[i]], sc[right_range[i]], 0);
        int64_t next_sum = read(state[left_id[i]], 0, BASE - 1, sc[0], sc[right_range[i]]);
        TreeNode* new_root = change(temp_root, 0, BASE - 1, sc[right_range[i]], sc[right_range[i]], next_sum);
        state.push_back(new_root);
    }
    int64_t res = read(state.back(), 0, BASE - 1, 0, BASE - 1);

    cout << res;

    return 0;
}