#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6+10;
int fa[maxn];
const int mod = 1e9+7;
typedef long long ll;
int find_fa(int x){
    return x == fa[x]?x:fa[x]=find_fa(fa[x]);
}
int main()
{
    int n, m;
    ll ans=1;
    scanf("%d%d", &n, &m);
    int l, r;
    for(int i=1; i<maxn; i++) fa[i] = i;
    int cnt = n;
    while(m--){
        scanf("%d%d", &l, &r);
        for(int i=find_fa(l); i<=r; i=find_fa(i+1)){
            //merge to the most right.
            fa[i] = i+1;
            cnt--;
        }
        ans = ans*cnt%mod;
    }
    printf("%lld\n", ans);
    return 0;
}