#include <bits/stdc++.h>
using namespace std;
#define LL long long
#define F first
#define S second
#define pii pair<int,int>
#define piii pair<pair<int,int>,int>
const int N = 2e5+10;
const int M = 5e3+10;
const LL INF = 1e9;
const LL LINF = 1e14;
const LL MOD = 1e9+7;
const double PI = 3.141592653589793;
LL add(LL a,LL b){
return (a+b)%MOD;
}
struct node {
node *lc,*rc;
LL sum = 0,l,r;
node():lc(NULL),rc(NULL),sum(0){};
};
void update(node * &v,int l,int r,int pos,LL val){
if(v==NULL){
v = new node();
v->l = l;v->r = r;
}
if(l==r){
v->sum = add(v->sum,val);
return ;
}
int mid = (l+r)/2;
if(pos<=mid)
update(v->lc,l,mid,pos,val);
else
update(v->rc,mid+1,r,pos,val);
v->sum = add((v->lc==NULL?0:v->lc->sum),(v->rc==NULL?0:v->rc->sum));
}
LL get(node * &v,int l,int r,int tl,int tr){
if(v==NULL){
v = new node();
v->l = l;v->r = r;
}
if(tl>=l&&tr<=r)
return v->sum;
if(tl>r||tr<l)
return 0;
int mid = (tl+tr)/2;
return add(get(v->lc,l,r,tl,mid),get(v->rc,l,r,mid+1,tr));
}
node *root;
int main(){
//freopen("out.txt","w",stdout);
int n;
scanf("%d",&n);
update(root,0,INF,0,1);
LL ans = 0;
for(int i=1;i<=n;i++){
int l,r;
scanf("%d%d",&l,&r);
for(int j=r;j>=l;j--){
update(root,0,INF,j,get(root,0,j-1,0,INF));
ans = add(ans,get(root,0,j-1,0,INF));
}
}
printf("%lld\n",ans);
}
