#include <bits/stdc++.h>
using namespace std;
int segT[8000005];
int lb[8000005];
int rb[8000005];
vector<int> cmpsegT[8000005];
vector<int> cmpsegTmn[8000005];
vector<int> cmpsegTmx[8000005];
vector<pair<int,int> > pts;
void build(int c,int l,int r){
lb[c] = l;
rb[c] = r;
if(l == r){
segT[c] = pts[l].first;
cmpsegT[c].push_back(0);
cmpsegT[c].push_back(pts[l].first);
cmpsegTmx[c].push_back(0);
cmpsegTmx[c].push_back(-1);
cmpsegTmn[c].push_back(0);
cmpsegTmn[c].push_back(2);
return;
}
int k = (l + r)/2;
build(2*c,l,k);
build(2*c+1,k+1,r);
segT[c] = min(segT[2*c],segT[2*c+1]);
int ll = 1;
int rr = 1;
cmpsegT[c].push_back(0);
cmpsegTmx[c].push_back(0);
cmpsegTmn[c].push_back(0);
while(ll < cmpsegT[2*c].size() && rr < cmpsegT[2*c+1].size()){
if(cmpsegT[2*c][ll] < cmpsegT[2*c+1][rr]){
cmpsegT[c].push_back(cmpsegT[2*c][ll]);
cmpsegTmx[c].push_back(-1);
cmpsegTmn[c].push_back(2);
ll++;
}else{
cmpsegT[c].push_back(cmpsegT[2*c+1][rr]);
cmpsegTmx[c].push_back(-1);
cmpsegTmn[c].push_back(2);
rr++;
}
}
while(ll < cmpsegT[2*c].size()){
cmpsegT[c].push_back(cmpsegT[2*c][ll]);
cmpsegTmx[c].push_back(-1);
cmpsegTmn[c].push_back(2);
ll++;
}
while(rr < cmpsegT[2*c+1].size()){
cmpsegT[c].push_back(cmpsegT[2*c+1][rr]);
cmpsegTmx[c].push_back(-1);
cmpsegTmn[c].push_back(2);
rr++;
}
}
void updatemin(vector<int>& FT,int idx,int amt){
while(idx < FT.size()){
FT[idx] = min(FT[idx],amt);
idx += idx & -idx;
}
}
void updatemax(vector<int>& FT,int idx,int amt){
while(idx < FT.size()){
FT[idx] = max(FT[idx],amt);
idx += idx & -idx;
}
}
void update(int c,int idx,int val){
if(lb[c] == rb[c]){
//cmpsegT[c][1] = val;
updatemin(cmpsegTmn[c],1,val);
updatemax(cmpsegTmx[c],1,val);
return;
}
int k = (lb[c] + rb[c])/2;
if(idx <= k){
update(2*c,idx,val);
}else{
update(2*c+1,idx,val);
}
idx = lower_bound(cmpsegT[c].begin(),cmpsegT[c].end(),pts[idx].first) - cmpsegT[c].begin();
updatemin(cmpsegTmn[c],idx,val);
updatemax(cmpsegTmx[c],idx,val);
}
int query(int c,int l,int r){
if(lb[c] == l && rb[c] == r) return segT[c];
int k = (lb[c] + rb[c])/2;
if(l <= k && k < r) return min(query(2*c,l,k),query(2*c+1,k+1,r));
else if(r <= k) return query(2*c,l,r);
else return query(2*c+1,l,r);
}
int qmin(vector<int>& FT,int idx){
int mn = 1e9;
while(idx > 0){
mn = min(mn,FT[idx]);
idx -= idx & -idx;
}
return mn;
}
int qmax(vector<int>& FT,int idx){
int mx = -1;
while(idx > 0){
mx = max(mx,FT[idx]);
idx -= idx & -idx;
}
return mx;
}
int getmin(int c,int l,int r,int x){
if(lb[c] == l && rb[c] == r) return qmin(cmpsegTmn[c],lower_bound(cmpsegT[c].begin(),cmpsegT[c].end(),x)-cmpsegT[c].begin()-1);
int k = (lb[c] + rb[c])/2;
if(l <= k && k < r) return min(getmin(2*c,l,k,x),getmin(2*c+1,k+1,r,x));
else if(r <= k) return getmin(2*c,l,r,x);
else return getmin(2*c+1,l,r,x);
}
int getmax(int c,int l,int r,int x){
if(lb[c] == l && rb[c] == r) return qmax(cmpsegTmx[c],lower_bound(cmpsegT[c].begin(),cmpsegT[c].end(),x)-cmpsegT[c].begin()-1);
int k = (lb[c] + rb[c])/2;
if(l <= k && k < r) return max(getmax(2*c,l,k,x),getmax(2*c+1,k+1,r,x));
else if(r <= k) return getmax(2*c,l,r,x);
else return getmax(2*c+1,l,r,x);
}
int main(){
int n;
scanf("%d",&n);
int a,b;
for(int i = 0; i < n; i++){
scanf("%d%d",&a,&b);
pts.emplace_back(a,b);
}
sort(pts.begin(),pts.end(),[](pair<int,int> x,pair<int,int> y){
return x.second < y.second;
});
build(1,0,pts.size()-1);
int c = 0;
for(int i = 0; i < n; i++){
int idx = upper_bound(pts.begin(),pts.end(),make_pair(0,pts[i].first),[](pair<int,int> x,pair<int,int> y){
return x.second < y.second;
}) - pts.begin();
bool ok = false;
if(idx <= i-1 && query(1,idx,i-1) < pts[i].first){
ok = true;
if(getmin(1,idx,i-1,pts[i].first) != getmax(1,idx,i-1,pts[i].first)){
printf("0\n");
return 0;
}else{
update(1,i,!getmin(1,idx,i-1,pts[i].first));
}
}
if(!ok){
c++;
update(1,i,0);
}
}
int ans = 1;
for(int i = 0; i < c; i++){
ans *= 2;
ans %= 1000000007;
}
printf("%d\n",ans);
return 0;
}
