#include <bits/stdc++.h>
using namespace std;
#define int long long
const long long MOD = 1e9 + 7;
int N, M;
int inp1, inp2;
deque<pair<int, int> > v1, v2;
int dv[500010][30], v[500010][30], prefix[500010][30];
int pow6[500010];
bool active[500010];
vector<pair<int, int> > curstack;
int lastl1[500010];
int lastl2[500010];
bool lasplace[500010][2];
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
pow6[0] = 1;
for(int a=1; a<500010; a++){
pow6[a] = pow6[a-1] * 26;
pow6[a] %= MOD;
}
cin >> N >> M;
for(int a=0; a<M; a++){
cin >> inp1 >> inp2;
if(inp1 < inp2){
//then larger then
v1.push_back({inp1, inp2-1});
}
else{
v2.push_back({inp2, inp1-1});
}
}
sort(v1.begin(), v1.end());
sort(v2.begin(), v2.end());
for(int a=1; a<=N; a++){
while(!curstack.empty() && curstack.back().second < a){
curstack.pop_back();
}
while(!v1.empty() && v1[0].first <= a){
curstack.push_back(v1[0]);
v1.pop_front();
}
lastl1[a] = (curstack.empty() ? INT_MAX : curstack.back().first-1);
}
for(int a=1; a<=N; a++){
while(!curstack.empty() && curstack.back().second < a){
curstack.pop_back();
}
while(!v2.empty() && v2[0].first <= a){
curstack.push_back(v2[0]);
v2.pop_front();
}
lastl2[a] = (curstack.empty() ? INT_MAX : curstack.back().first-1);
}
for(int a=1; a<=N; a++){
//cout << lastl1[a] << ' ' << lastl2[a] << '\n';
}
for(int a=1; a<=26; a++){
dv[0][a] = 1LL;
prefix[0][a] = (long long)a;
v[0][a] = 0LL;
}
for(int a=1; a<N; a++){
int sm = 0;
for(int b=1; b<=26; b++){
sm += v[a-1][b];
sm %= MOD;
if(sm < 0) sm += MOD;
}
for(int b=1; b<=26; b++){
v[a][b] = sm;
}
for(int b=1; b<=26; b++){
if(lastl1[a] != INT_MAX){
//v[a][b] += (prefix[lastl1[a]][26] - prefix[lastl1[a]][b]) % MOD;
v[a][b] += prefix[lastl1[a]][b-1];
}
v[a][b] %= MOD;
if(v[a][b] < 0) v[a][b] += MOD;
if(lastl2[a] != INT_MAX){
//v[a][b] += prefix[lastl2[a]][b-1];
v[a][b] += (prefix[lastl2[a]][26] - prefix[lastl2[a]][b]) % MOD;
}
v[a][b] %= MOD;
if(v[a][b] < 0) v[a][b] += MOD;
}
for(int b=1; b<=26; b++){
dv[a][b] = pow6[a] - v[a][b];
dv[a][b] %= MOD;
if(dv[a][b] < 0) dv[a][b] += MOD;
prefix[a][b] = prefix[a][b-1] + dv[a][b];
prefix[a][b] %= MOD;
if(prefix[a][b] < 0) prefix[a][b] += MOD;
}
}
cout << prefix[N-1][26];
}
