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

pair<ll, ll> mines[300009];
ll max_left[300009];
ll min_left[300009];
ll tree[(1 << 20) + 9];
ll dp[2][3000009];
const ll MOD = 1000000007;

struct node {
    ll i;
    ll max_right_range;
    ll max_right_activation;

    node(ll _i, ll _max_right_range, ll _max_right_activation) {
        i = _i;
        max_right_range = _max_right_range;
        max_right_activation = _max_right_activation;
    }
};

ll first(ll x){
    ll p = 1;
    ll q = x;
    while(p < q){
        ll m = (p + q) / 2;
        if(mines[m].first < mines[x].first - mines[x].second)
            p = m + 1;
        else
            q = m;
    }
    return p;
}


ll get_min(ll p, ll q) {
    ll res = 1000000009;
    p += (1 << 19) - 1;
    q += (1 << 19) - 1;
    while(p <= q and p > 0 and q > 0){
        if(p % 2 == 1)
            res = min(res, tree[p++]);
        if(q % 2 == 0)
            res = min(res, tree[q--]);
        p /= 2;
        q /= 2;
    }
    return res;
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    ll n;
    cin >> n;
    for(ll i = 1; i <= n; i++) {
        cin >> mines[i].first >> mines[i].second;
    }

    fill(tree, tree + (1 << 20) + 5, 1000000009);
    for(ll i = 1; i <= n; i++){
        ll begin = first(i);
        max_left[i] = (begin == i ? i : get_min(begin, i));
        ll v = i + (1 << 19) - 1;
        tree[v] = max_left[i];
        while(v > 1){
            v /= 2;
            tree[v] = min(tree[2 * v], tree[2 * v + 1]);
        }
    }

    stack<node> min_left_stack;
    min_left_stack.push(node(1, mines[1].first + mines[1].second, mines[1].first));
    for(ll i = 2; i <= n; i++) {
        while(not min_left_stack.empty() and min_left_stack.top().max_right_range < mines[i].first)
            min_left_stack.pop();
        if(not min_left_stack.empty()) {
            min_left[i] = min_left_stack.top().i;
            if((mines[i].first - mines[i].second) <= min_left_stack.top().max_right_activation) {
                min_left_stack.top().i = i;
                min_left_stack.top().max_right_range = max(min_left_stack.top().max_right_range, mines[i].first + mines[i].second);
                min_left_stack.top().max_right_activation = mines[i].first;
            }
        }
        min_left_stack.push(node(i, mines[i].first + mines[i].second, mines[i].first));
    }

    dp[0][1] = 1;
    dp[1][1] = 1;
    for(ll i = 2; i <= n; i++){
        if(max_left[i] == 0)
            dp[1][i] = 1;

        if(max_left[i] > 0)
            dp[1][i] = (dp[1][max_left[i] - 1] + dp[0][max_left[i] - 1]) % MOD;

        dp[0][i] = (dp[0][i - 1] + dp[1][i - 1]) % MOD;

        if(min_left[i] != 0)
            dp[0][i] = (MOD + dp[0][i] - dp[1][min_left[i]]) % MOD;
    }
    cout << (dp[0][n] + dp[1][n]) % MOD << "\n";
    
    return 0;
}