/**
____ ____ ____ ____ ____ ____
||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][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][1][j] = 1;
}
for (int i = 1; i <= n - 1; i ++)
{
for (int j = 1; j <= i; j ++)
{
bool small = false, big = false;
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;
if (i - j < con[d].first)
small = true;
}
else
{
if (con[d].second >= i + 1 || con[d].first < i + 1)
continue;
if (i - j < con[d].second)
big = true;
}
}
///cout << small << " : " << big << endl;
if (!small)
{
ll sum = 0;
for (int c = 0; c < 26; c ++)
{
dp[i + 1][1][c] += sum;
if (dp[i + 1][1][c] >= mod)
dp[i + 1][1][c] -= mod;
sum += dp[i][j][c];
if (sum >= mod)
sum -= mod;
}
}
if (!big)
{
ll sum = 0;
for (int c = 25; c >= 0; c --)
{
dp[i + 1][1][c] += sum;
if (dp[i + 1][1][c] >= mod)
dp[i + 1][1][c] -= mod;
sum += dp[i][j][c];
if (sum >= mod)
sum -= mod;
}
}
for (int c = 0; c < 26; c ++)
{
dp[i + 1][j + 1][c] += dp[i][j][c];
if (dp[i + 1][j + 1][c] >= mod)
dp[i + 1][j + 1][c] -= mod;
}
}
}
ll ans = 0;
for (int j = 1; j <= n; j ++)
for (int c = 0; c < 26; c ++)
{
ans = ans + dp[n][j][c];
if (ans >= mod)
ans -= mod;
}
cout << ans << endl;
}
int main()
{
solve();
return 0;
}
