/**
____ ____ ____ ____ ____ ____
||l |||e |||i |||n |||a |||d ||
||__|||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|/__\|
**/
#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
typedef long long ll;
void speed()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
}
const int maxn = 510, maxa = 1e6 + 10;
const ll mod = 1e9 + 7;
int n, a[maxn], b[maxn];
ll dp[maxn], fp[maxa];
void solve()
{
cin >> n;
bool diff = false;
for (int i = 1; i <= n; i ++)
{
cin >> a[i] >> b[i];
if (a[i] != b[i])
diff = true;
}
if (!diff)
{
ll ans = 0;
for (int i = 1; i <= n; i ++)
{
dp[i] = 1;
for (int j = 1; j < i; j ++)
{
if (a[i] > a[j])
dp[i] = (dp[i] + dp[j]) % mod;
}
ans = (ans + dp[i]) % mod;
}
cout << ans << endl;
}
else
{
set < int > st;
for (int i = 1; i <= n; i ++)
for (int j = a[i]; j <= b[i]; j ++)
st.insert(j);
map < int, int > mp;
int idx = 0;
for (int cur : st)
mp[cur] = ++ idx;
fp[0] = 1;
for (int i = 1; i <= n; i ++)
{
a[i] = mp[a[i]];
b[i] = mp[b[i]];
ll sum = 0;
for (int j = 0; j < a[i]; j ++)
{
sum = sum + fp[j];
if (sum >= mod)
sum -= mod;
}
ll lsum = sum;
for (int j = a[i]; j <= b[i]; j ++)
{
sum = sum + fp[j];
if (sum >= mod)
sum -= mod;
fp[j] = (fp[j] + lsum);
if (fp[j] >= mod)
fp[j] -= mod;
lsum = sum;
}
/**for (int j = 0; j < 10; j ++)
cout << fp[j] << " ";
cout << endl;*/
}
ll ans = 0;
for (int i = 1; i < maxa; i ++)
{
ans = ans + fp[i];
if (ans >= mod)
ans -= mod;
}
cout << ans << endl;
}
}
int main()
{
solve();
return 0;
}
