/**
____ ____ ____ ____ ____ ____
||l |||e |||i |||n |||a |||d ||
||__|||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|/__\|
**/
#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
typedef long long ll;
void speed()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
}
const ll mod = 1000000007;
const int maxm = 5e5 + 10;
const int maxn = 210;
int n, m;
ll dp[maxn][30];
pair < int, int > con[maxm];
void solve()
{
cin >> n >> m;
for (int i = 1; i <= m; i ++)
{
cin >> con[i].first >> con[i].second;
}
for (int j = 0; j < 26; j ++)
{
dp[1][j] = 1;
}
for (int i = 1; i <= n - 1; i ++)
{
int pt_big = n, pt_small = n;
for (int d = 1; d <= m; d ++)
{
if (con[d].first == con[d].second)
continue;
if (con[d].first < con[d].second)
{
if (con[d].first >= i + 1 || con[d].second < i + 1)
continue;
pt_small = min(pt_small, i - con[d].first + 1);
/**if (i - j < con[d].first)
{
small = true;
}*/
}
else
{
if (con[d].second >= i + 1 || con[d].first < i + 1)
continue;
pt_big = min(pt_big, i - con[d].second + 1);
/**if (i - j < con[d].second)
big = true;*/
}
}
///cout << i << " : " << pt_big << " : " << pt_small << endl;
for (int j = 1; j <= i; j ++)
{
if (j < pt_small)
{
ll sum = 0;
for (int c = 0; c < 26; c ++)
{
dp[i + 1][c] += sum;
if (dp[i + 1][c] >= mod)
dp[i + 1][c] -= mod;
sum += dp[i - j + 1][c];
if (sum >= mod)
sum -= mod;
}
}
if (j < pt_big)
{
ll sum = 0;
for (int c = 25; c >= 0; c --)
{
dp[i + 1][c] += sum;
if (dp[i + 1][c] >= mod)
dp[i + 1][c] -= mod;
sum += dp[i - j + 1][c];
if (sum >= mod)
sum -= mod;
}
}
}
///cout << small << " : " << big << endl;
}
ll ans = 0;
for (int i = 1; i <= n; i ++)
for (int c = 0; c < 26; c ++)
{
ans = ans + dp[i][c];
if (ans >= mod)
ans -= mod;
}
cout << ans << endl;
}
int main()
{
solve();
return 0;
}
