#include <bits/stdc++.h>
#define fio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define fo(i,a,b,c) for(int i = a ; i<=b ; i+=c)
#define fol(i,a,b,c) for(int i = a ; i>=b ; i-=c)
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pow(z) (1LL*(z)*(z))
#define M 1000000007
 
using namespace std;
 
int n, k, p[200005];
pii w[11];
long long t[800005];
 
void up(int i, int l, int r, int pos, int val){
    if(l == r){ t[i] = val; return; }
    int m = (l + r) / 2;
    if(pos <= m)up(i * 2, l, m, pos, val);
    else up(i * 2 + 1, m + 1, r, pos, val);
    t[i] = (t[i * 2]%M + t[i * 2 + 1]%M)%M;
}
 
long long sum(int i, int l, int r, int x, int y){
    if(l > y || r < x) return 0;
    if(x <= l && r <= y) return t[i];
    int m = (l + r) / 2;
    return (sum(i * 2, l, m, x, y)%M + sum(i * 2 + 1, m + 1, r, x, y)%M)%M;
}
 
int main(){
    fio;
//    freopen("ucute.inp","r",stdin);
//    freopen("ucute.out","w",stdout);
 
    cin >> n >> k;
    fo(i, 1, k, 1) cin >> w[i].fi >> w[i].se;
    sort(w+1,w+k+1);
    p[1] = 1;
    up(1, 1, n, 1, 1);
    fo(i, 2, n, 1){
        int last = w[1].fi;
        fo(j, 1, k, 1){
            int l = max(last, w[j].fi);
            int r = min(i - 1, w[j].se);
            if(l >= i || l > r) continue;
            p[i] = ((p[i]%M) + sum(1, 1, n, i - r, i - l))%M;
            last = r + 1;
        }
        up(1, 1, n, i, p[i]);
    }
    cout << p[n];
}
 

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5 2
1 1
3 5