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#include <cstdio>
#include <vector>
#include <set>

const int max_n = 500100;
int n;
long long a[max_n];
long long r[max_n];

int top;
std::pair<long long, int> stack[max_n];

std::vector<int> G[max_n];
std::vector<int> current;
std::vector<std::vector<int>> solution;
int D[max_n], S[max_n], InS[max_n], C[max_n];
int ile, tt;
int delta[max_n], eta[max_n]; 
int best;

int m;
std::vector<int> DAG[max_n];
int DMN[max_n], DMX[max_n];
int dvis[max_n];

const int mod = 1000000007;

void dfsX(int v) {
    dvis[v] = 1;
    int mx = DMN[v], mn = DMX[v];
    for (int i = 0; i < DAG[v].size(); ++i) {
        if (dvis[DAG[v][i]] == 0) {
            dfsX(DAG[v][i]);
        }
        DMN[v] = std::min(DMN[v], DMN[DAG[v][i]]);
        DMX[v] = std::max(DMX[v], DMX[DAG[v][i]]);
    }
}

void dfs(int v) {
  S[top++] = v;
  InS[v] = 1;
  delta[v] = eta[v] = ++tt; 
  D[v] = 1;
  for (int i = 0; i < G[v].size(); ++i) {
    if (D[G[v][i]] == 0) {
      dfs(G[v][i]);
      eta[v] = std::min(eta[v], eta[G[v][i]]);
    } else if (delta[G[v][i]] < delta[v] && InS[G[v][i]])
      eta[v] = std::min(eta[v], delta[G[v][i]]);
  }
  if (delta[v] == eta[v]) {
    ++ile;
    current.clear();
    while (top > 0 && delta[v] <= delta[S[top - 1]]) {
      --top;
      InS[S[top]] = 0;
      C[S[top]] = ile;
      current.push_back(S[top] + 1);
    }
    solution.push_back(current);
  }
}
 
int lmSCCTarjanAlgo() {
  for (int i = 0; i < n; ++i) D[i] = InS[i] = 0;
  top = ile = tt = 0;
  for (int i = 0; i < n; ++i) if (!D[i]) dfs(i);
  return ile;
}

const int czapa = 524288;
long long tree[2 * czapa + 1];
std::vector<std::pair<int, long long>> pending[max_n];

void add(int index, long long val) {
    index += czapa;
    while (index >= 1) {
        tree[index] += val;
        index >>= 1;
    }
}

long long sum(int index) {
    index += czapa;
    long long ret = 0;
    while (index > 1) {
        if (index & 1) ret += tree[index - 1];
        index >>= 1;
    }
    return ret % mod;
}


int main() {
    scanf("%d", &n);
    for (int i = 0; i < n; ++i) {
        scanf("%lld %lld", &a[i], &r[i]);
    }

    top = 1;
    stack[0].first = a[0] + r[0];
    stack[0].second = 0;
    for (int i = 1; i < n; ++i) {
        while (top > 0 && stack[top - 1].first < a[i]) --top;
        if (top > 0) {
            G[stack[top - 1].second].push_back(i);
        }
        while (top > 0 && stack[top - 1].first <= a[i] + r[i]) --top;
        stack[top].first = a[i] + r[i];
        stack[top].second = i;
        ++top;
    }

    top = 1;
    stack[0].first = a[n - 1] - r[n - 1];
    stack[0].second = n - 1;
    for (int i = n - 2; i >= 0; --i) {
        while (top > 0 && stack[top - 1].first > a[i]) --top;
        if (top > 0) {
            G[stack[top - 1].second].push_back(i);
        }
        while (top > 0 && stack[top - 1].first >= a[i] - r[i]) --top;
        stack[top].first = a[i] - r[i];
        stack[top].second = i;
        ++top;
    }

//    for (int i = 0; i < n; ++i) {
//        printf("%d:", i);
//        for (int j = 0; j < G[i].size(); ++j) {
//            printf (" %d", G[i][j]);
//        }
//        printf("\n");
//    }

    lmSCCTarjanAlgo();
//    for (int i = 0; i < n; ++i) {
//        printf("C: %d: %d\n", i, C[i]);
//    }
    m = ile;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < G[i].size(); ++j) {
            if (C[i] != C[G[i][j]]) DAG[C[i] - 1].push_back(C[G[i][j]] - 1);
        }
    }
    for (int i = 0; i < m; ++i) DMX[i] = -1, DMN[i] = 1000000000, dvis[i] = 0;
    for (int i = 0; i < n; ++i) {
        DMX[C[i] - 1] = std::max(DMX[C[i] - 1], i);
        DMN[C[i] - 1] = std::min(DMN[C[i] - 1], i);
    }
//    for (int i = 0; i < n; ++i) {
//        printf("V: %d: %d %d\n", i, DMN[C[i] - 1], DMX[C[i] - 1]);
//    }
    for (int i = 0; i < m; ++i) {
        if (dvis[i] == 0) dfsX(i);
    }
    for (int i = 0; i < 2 * czapa + 1; ++i) {
        tree[i] = 0;
    }
    add(0, 1);
    long long ret = 1;
//    std::vector<std::pair<std::pair<int, int>, long long>> X;
//    X.push_back(std::make_pair(std::make_pair(0, 0), 1));
    std::set<std::pair<int, int>> S;
    for (int i = 1; i <= n; ++i) {
//        printf("%d\n", i);
        std::pair<int, int> rt = std::make_pair(DMN[C[i - 1] - 1] + 1, DMX[C[i - 1] - 1] + 1);
        if (S.find(rt) == S.end()) {
            S.insert(rt);
            long long lret = sum(rt.first);
//            long long lret2 = 0;
//            for (int j = 0; j < X.size(); ++j) {
//                if (X[j].first.first < rt.first && X[j].first.second < i) {
//                    lret2 = (lret2 + X[j].second) % mod;
//                }
//            }
//            printf("V: %d: %d %d\n", i, rt.first, rt.second);
//            printf("W: %lld vs %lld\n", lret, lret2);
//            X.push_back(std::make_pair(std::make_pair(i, rt.second), lret2));
            pending[rt.second]. push_back(std::make_pair(i, lret));
            ret = (ret + lret) % mod;
        }
        for (int j = 0; j < pending[i].size(); ++j) {
            add(pending[i][j].first, pending[i][j].second);
        }
   } 
    printf("%lld\n", ret);  
    return 0;
}