#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <set>
#include <map>
#include <time.h>
using namespace std;
long long MOD=1e9+7,now=1;
long long a[505];
long long b[505];
struct A
{
long long l,r;
long long nxl,nxr;
long long con;
}Node[2000005];
void build(long long l,long long r,long long here)
{
Node[here].l=l;
Node[here].r=r;
Node[here].con=0;
Node[here].nxl=-1;
Node[here].nxr=-1;
}
long long Find(long long l,long long r,long long here)
{
if(here<0) return 0;
if(Node[here].l==l&&Node[here].r==r) return Node[here].con;
if(r<=(Node[here].l+Node[here].r)/2) return Find(l,r,Node[here].nxl);
if(l>(Node[here].l+Node[here].r)/2) return Find(l,r,Node[here].nxr);
return (Find(l,(Node[here].l+Node[here].r)/2,Node[here].nxl)+Find((Node[here].l+Node[here].r)/2+1,r,Node[here].nxr))%MOD;
}
void cha(long long where,long long con,long long here)
{
//printf("%lld %lld %lld %lld %lld\n",where,con,here,Node[here].l,Node[here].r);
Node[here].con+=con;
Node[here].con%=MOD;
if(Node[here].l==where&&Node[here].r==where)
{
return;
}
if(where<=(Node[here].l+Node[here].r)/2)
{
if(Node[here].nxl==-1)
{
Node[here].nxl=now++;
build(Node[here].l,(Node[here].l+Node[here].r)/2,Node[here].nxl);
}
cha(where,con,Node[here].nxl);
}
else
{
if(Node[here].nxr==-1)
{
Node[here].nxr=now++;
build((Node[here].l+Node[here].r)/2+1,Node[here].r,Node[here].nxr);
}
cha(where,con,Node[here].nxr);
}
}
int main()
{
//srand(time(NULL));
long long N,M,i,j;
scanf("%lld",&N);
for(i=1;i<=N;i++) scanf("%lld %lld",&a[i],&b[i]);
build(0,1e9,0);
cha(0,1,0);
//printf("aa\n");
for(i=1;i<=N;i++)
{
for(j=b[i];j>=a[i];j--)
{
//printf("%lld %lld\n",i,j);
cha(j,Find(0,j-1,0),0);
}
}
printf("%lld\n",Find(1,1e9,0));
return 0;
}
/*
2
32 47
18 78
*/
