#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <set>
typedef long long llong;
const int MAXN = 1e6 + 10;
const int MOD = 1e9 + 7;
const llong INF = 2e18;
const int MAXLOG = 21;
int n;
struct Fenwick
{
int tree[2 * MAXN];
void reset()
{
std::fill(tree + 1, tree + 1 + 2 * n, 0);
}
void update(int idx, int val)
{
for (; idx <= 2 * n ; idx += idx & (-idx))
{
tree[idx] += val;
}
}
int query(int idx)
{
int res = 0;
for (; idx ; idx -= idx & (-idx))
{
res += tree[idx];
}
return res;
}
int findKth(int k)
{
int idx = 0;
for (int lg = MAXLOG - 1 ; lg >= 0 ; --lg)
{
if (idx + (1 << lg) <= 2 * n && tree[idx + (1 << lg)] < k)
{
idx += (1 << lg);
k -= tree[idx];
}
}
return idx + 1;
}
};
Fenwick fenwick;
int perm[MAXN];
int l[MAXN];
int r[MAXN];
int maxR[MAXN];
int minL[MAXN];
std::vector <int> g[MAXN];
bool vis[MAXN];
void dfs(int node)
{
vis[node] = true;
for (const int &u : g[node])
{
if (vis[u])
{
continue;
}
dfs(u);
}
}
void solve()
{
std::iota(perm + 1, perm + 1 + n, 1);
std::sort(perm + 1, perm + 1 + n, [&](int x, int y)
{
return r[x] > r[y];
});
minL[0] = 2 * n + 1;
for (int i = 1 ; i <= n ; ++i)
{
int k = fenwick.query(l[perm[i]] - 1) + 1;
int res = fenwick.findKth(k);
if (k <= i - 1 && res <= r[perm[i]])
{
minL[perm[i]] = res;
} else
{
minL[perm[i]] = 2 * n + 1;
}
fenwick.update(l[perm[i]], 1);
}
fenwick.reset();
std::sort(perm + 1, perm + 1 + n, [&](int x, int y)
{
return l[x] < l[y];
});
for (int i = 1 ; i <= n ; ++i)
{
int k = fenwick.query(r[perm[i]]);
int res = fenwick.findKth(k);
if (k > 0 && res >= l[perm[i]])
{
maxR[perm[i]] = res;
} else
{
maxR[perm[i]] = 0;
}
fenwick.update(r[perm[i]], 1);
}
for (int i = 1 ; i <= n ; ++i)
{
if (minL[i] < maxR[i])
{
std::cout << 0 << '\n';
return;
}
}
for (int i = 1 ; i <= n ; ++i)
{
for (int j = i + 1 ; j <= n ; ++j)
{
if (l[perm[j]] < r[perm[i]] && r[perm[i]] < r[perm[j]])
{
g[i].push_back(j);
g[j].push_back(i);
}
}
}
int ans = 1;
for (int u = 1 ; u <= n ; ++u)
{
if (!vis[u])
{
dfs(u);
ans *= 2;
if (ans >= MOD) ans -= MOD;
}
}
std::cout << ans << '\n';
}
void input()
{
std::cin >> n;
for (int i = 1 ; i <= n ; ++i)
{
std::cin >> l[i] >> r[i];
}
}
void fastIOI()
{
std::ios_base :: sync_with_stdio(0);
std::cout.tie(nullptr);
std::cin.tie(nullptr);
}
int main()
{
fastIOI();
input();
solve();
return 0;
}
