ACTIV

#include<bits/stdc++.h>
#define endl '\n'
#define INF 999999999

typedef long long int ll;

using namespace std;

int n;
vector <pair<int ,int> > interval;
vector <pair<int ,int> > interval2;
bool dp[100001];
ll dpp[100001];
const ll mod=100000000;

bool sortBySec(const pair<int,int>a, const pair<int,int> b){
  return a.second<b.second;
}

int next(int i){//returns the first interval which has its startTime >= EndTime of the ith interval
  auto it = lower_bound(interval2.begin(), interval2.end(), make_pair(interval[i].second,0));
  if(it==interval2.end())return n+1;
  pair<int,int> m=*it;//cout << m.first << ' ' << i << ' ';

  int lo=0, hi=n-1, mid;
  while(lo<=hi){
    mid=lo+(hi-lo)/2;
    if(interval[mid]==m){
        break;
    }
    if(interval[mid].second>m.second){
        hi=mid-1;
    }else{
        lo=mid+1;
    }
  }
  return mid;
}

ll DP(int i){//int i represents ith interval the intervals sorted by their endtime
  if(i==n-1)return 1;
  if(i>=n)return 0;//handles when next(i) returns n+1
  if(dp[i])return dpp[i];
  dp[i]=1;
  dpp[i] = (DP(next(i))%mod+(1 + DP(i+1))%mod)%mod;
  return dpp[i];
}
void makeFalse(){
  for(int i=0; i<n; i++){
    dp[i]=dpp[i]=0;
    }
}
int main(){
  ios_base::sync_with_stdio(false);cin.tie(NULL);
  int s,e;
  ll ans;
  while(cin >> n && n!=-1){
    interval.clear();interval2.clear();
    for(int i=0; i<n; i++){
      cin >> s >> e;
      interval.push_back({s,e});
      interval2.push_back({s,e});
    }
    sort(interval.begin(), interval.end(), sortBySec);
    sort(interval2.begin(),interval2.end());
    makeFalse();
    ans = DP(0);
    int res = 1 + floor(log10(ans));
    for(int i=0; i<8-res; i++)cout << 0;
    cout << ans << endl;
  }
}