#include <bits/stdc++.h>
using namespace std;
//we are perpetually trapped in a cycle of death and rebirth
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int n,m;
cin >> n >> m;
int lefu[n],lefd[n];
memset(lefu,-1,sizeof(lefu));
memset(lefd,-1,sizeof(lefd));
vector<pair<int,int> > rangu,rangd;
for(int i=0; i<m; i++){
int a,b;
cin >> a >> b;
a--; b--;
if(a<b) rangd.push_back({a,b});
else rangu.push_back({b,a});
}
sort(rangd.begin(),rangd.end());
sort(rangu.begin(),rangu.end());
stack<pair<int,int> > s;
int c1=0,c2=0;
for(int i=0; i<n; i++){
while(!s.empty()&&s.top().second<i){
s.pop();
}
while(c1<(int)rangd.size()&&rangd[c1].first<i){
s.push(rangd[c1]);
c1++;
}
if(!s.empty()) lefd[i]=s.top().first;
}
while(!s.empty()){
s.pop();
}
for(int i=0; i<n; i++){
while(!s.empty()&&s.top().second<i){
s.pop();
}
while(c2<(int)rangu.size()&&rangu[c2].first<i){
s.push(rangu[c2]);
c2++;
}
if(!s.empty()) lefu[i]=s.top().first;
}
long long dv[n][26],v[n][26];
memset(dv,0,sizeof(dv));
memset(v,0,sizeof(v));
for(int i=0; i<26; i++){
v[0][i]=0;
dv[0][i]=1;
}
long long ts[500005];
ts[0]=1;
for(int i=1; i<500005; i++){
ts[i]=ts[i-1]*26%1000000007;
}
for(int i=1; i<n; i++){
long long cur=0,sum=0;
for(int j=0; j<26; j++) sum=(sum+v[i-1][j])%1000000007;
for(int j=25; j>=0; j--){
v[i][j]+=sum;
if(v[i][j]>=1000000007) v[i][j]-=1000000007;
if(lefu[i]==-1) continue;
if(j<25) cur+=dv[lefu[i]][j+1];
if(cur>=1000000007) cur-=1000000007;
v[i][j]+=cur;
if(v[i][j]>=1000000007) v[i][j]-=1000000007;
}
cur=0;
for(int j=0; j<26; j++){
if(lefd[i]==-1) continue;
if(j) cur+=dv[lefd[i]][j-1];
if(cur>=1000000007) cur-=1000000007;
v[i][j]+=cur;
if(v[i][j]>=1000000007) v[i][j]-=1000000007;
}
for(int j=0; j<26; j++){
dv[i][j]=ts[i]-v[i][j]+1000000007;
if(dv[i][j]>=1000000007) dv[i][j]-=1000000007;
//cout << v[i][j] << ' ' << dv[i][j] << '\n';
}
}
long long ans=0;
for(int i=0; i<26; i++) ans=(ans+dv[n-1][i])%1000000007;
cout << ans;
}
