//
#include <bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define o cout<<"BUG"<<endl;
#define FOR(i, j, n) for(int j = i; j < n; ++j)
#define forn(i, j, n) for(int j = i; j <= n; ++j)
#define nfor(i, j, n) for(int j = n; j >= i; --j)
#define all(v) v.begin(), v.end()
#define ld long double
#define ull unsigned long long
using namespace std;
const int maxn=5e5+100,LOG=17,mod=1e9+7;
int block = 226, timer = 0;
const ld EPS = 1e-18;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define IOS ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define bt(i) (1 << (i))
//#define int ll
const int inf=2e9;
#define y1 yy
#define prev pre
#define pii pair <int, int>
int n, m;
ll t[4*maxn][28][3], dp[maxn][28], temp[30];
multiset <int> st[4];
vector <pii> start[maxn], fin[maxn];
void upd(int v, int tl, int tr, int pos, ll val, int x, int ty)
{
if(pos < tl || tr < pos) return;
if(tl == tr)
{
t[v][x][ty] = val;
return;
}
upd(v * 2, tl, (tl + tr) / 2, pos, val, x, ty);
upd(v * 2 + 1, (tl + tr) / 2 + 1, tr, pos, val, x, ty);
t[v][x][ty] = (t[v * 2][x][ty] + t[v * 2 + 1][x][ty]) % mod;
}
ll get(int v, int tl, int tr, int l, int r, int x, int ty)
{
if(l > tr || r < tl) return 0;
if(l <= tl && tr <= r) return t[v][x][ty];
return (get(v * 2, tl, (tl + tr) / 2, l, r, x, ty) +
get(v * 2 + 1, (tl + tr) / 2 + 1, tr, l, r, x, ty)) % mod;
}
main()
{
IOS
cin >> n >> m;
forn(1, i, m)
{
int l, r, ty;
cin >> l >> r;
if(l < r) ty = 2;
else ty = 1, swap(l, r);
start[l].pb({r, ty});
fin[r].pb({l, ty});
}
st[1].insert(0);
st[2].insert(0);
forn(1, i, n)
{
for(auto j : start[i-1])
st[j.s].insert(i-1);
int L, L2;
L2 = max(*st[1].rbegin(), *st[2].rbegin()) + 1;
L = L2;
forn(0, j, 'z'-'a')
{
if(j > 0)
dp[i][j] = (dp[i][j] + get(1, 1, n, L, i-1, j-1, 1)) % mod;
if(j < 'z'-'a')
dp[i][j] = (dp[i][j] + get(1, 1, n, L, i-1, j+1, 2)) % mod;
}
if(*st[1].rbegin() < *st[2].rbegin())
{
auto it = *st[1].rbegin() + 1;
L = it;
FOR(0, j, 'z'-'a')
dp[i][j] = (dp[i][j] + get(1, 1, n, L, L2-1, j+1, 2)) % mod;
}
else
if(*st[1].rbegin() > *st[2].rbegin())
{
auto it = *st[2].rbegin() + 1;
L = it;
forn(1, j, 'z'-'a')
dp[i][j] = (dp[i][j] + get(1, 1, n, L, L2-1, j-1, 1)) % mod;
}
if(i == 1)
{
forn(0, j, 'z'-'a') dp[i][j] = 1;
}
/*cout << " FOR " << i << endl;
forn(0, j, 'z'-'a') cout << (char)(j + 'a') << " " << dp[i][j] << endl;
*/
forn(0, j, 'z'-'a')
{
if(j > 0)
temp[j] = (temp[j - 1] + dp[i][j]) % mod;
else
temp[j] = dp[i][j];
upd(1, 1, n, i, temp[j], j, 1);
// cout << "UPD " << i << " " << temp[j] << endl;
}
nfor(0, j, 'z'-'a')
{
if(j == 'z'-'a')
temp[j] = dp[i][j];
else
temp[j] = (temp[j + 1] + dp[i][j]) % mod;
// cout << "UPD " << i << " " << temp[j] << endl;
upd(1, 1, n, i, temp[j], j, 2);
}
/* o
for(auto j : st[1]) cout << j << " ";
cout << endl;
for(auto j : st[2]) cout << j << " ";
cout << endl;
for(auto j : fin[i]) cout << j.f << " " << j.s << endl;
cout << endl;*/
for(auto j : fin[i])
st[j.s].erase(st[j.s].find(j.f));
}
ll ans = 0;
forn(1, i, n)
{
forn(0, j, 'z'-'a') ans = (ans + dp[i][j]) % mod;
}
cout << ans;
}
