#include <bits/stdc++.h>
#define int long long
using namespace std;
template <const int32_t MOD> struct ModInt {
int32_t x;
ModInt() : x(0) {}
ModInt(long long u) : x(u % MOD) {
if (x < 0)
x += MOD;
}
friend bool operator==(const ModInt &a, const ModInt &b) {
return a.x == b.x;
}
friend bool operator!=(const ModInt &a, const ModInt &b) {
return a.x != b.x;
}
friend bool operator<(const ModInt &a, const ModInt &b) { return a.x < b.x; }
friend bool operator>(const ModInt &a, const ModInt &b) { return a.x > b.x; }
friend bool operator<=(const ModInt &a, const ModInt &b) {
return a.x <= b.x;
}
friend bool operator>=(const ModInt &a, const ModInt &b) {
return a.x >= b.x;
}
static ModInt sign(long long k) {
return ((k & 1) ? ModInt(MOD - 1) : ModInt(1));
}
ModInt &operator+=(const ModInt &m) {
x += m.x;
if (x >= MOD)
x -= MOD;
return *this;
}
ModInt &operator-=(const ModInt &m) {
x -= m.x;
if (x < 0LL)
x += MOD;
return *this;
}
ModInt &operator*=(const ModInt &m) {
x = (1LL * x * m.x) % MOD;
return *this;
}
friend ModInt operator-(const ModInt &a) {
ModInt res(a);
if (res.x)
res.x = MOD - res.x;
return res;
}
friend ModInt operator+(const ModInt &a, const ModInt &b) {
return ModInt(a) += ModInt(b);
}
friend ModInt operator-(const ModInt &a, const ModInt &b) {
return ModInt(a) -= ModInt(b);
}
friend ModInt operator*(const ModInt &a, const ModInt &b) {
return ModInt(a) *= ModInt(b);
}
static long long fp(long long u, long long k) {
long long res = 1LL;
while (k > 0LL) {
if (k & 1LL)
res = (res * u) % MOD;
u = (u * u) % MOD;
k /= 2LL;
}
return res;
}
static constexpr int mod() { return MOD; }
ModInt fastpow(long long k) { return ModInt(fp(x, k)); }
ModInt inv() {
assert(x);
return ModInt(fp(x, MOD - 2));
}
ModInt &operator/=(const ModInt &m) { return *this *= ModInt(m).inv(); }
friend ModInt operator/(const ModInt &a, const ModInt &b) {
return ModInt(a) *= ModInt(b).inv();
}
friend ostream &operator<<(ostream &out, const ModInt &a) {
return out << a.x;
}
friend istream &operator>>(istream &in, ModInt &a) { return in >> a.x; }
};
const int MOD = 1e9 + 7;
using Mint = ModInt<MOD>;
struct Contrainte {
int L, R;
bool inc;
};
signed main(void) {
ios_base::sync_with_stdio(false);
cin.tie(0);
int longueur, nbContraintes;
cin >> longueur >> nbContraintes;
vector<Contrainte> contraintes(nbContraintes);
for (int i = 0; i < nbContraintes; ++i) {
int A, B;
cin >> A >> B;
--A, --B;
if (A < B)
contraintes[i] = {A, B, false};
else
contraintes[i] = {B, A, true};
}
vector<array<Mint, 26>> dp(longueur);
dp[0].fill(1);
for (int i = 1; i < longueur; ++i) {
int LInc = -1, LDec = -1;
for (auto [L, R, inc] : contraintes) {
if (R >= i and L < i) {
if (inc)
LInc = max(LInc, L);
else
LDec = max(LDec, L);
}
}
for (int nxt = 0; nxt < 26; ++nxt) {
dp[i][nxt] = 0;
for (int old = 0; old < nxt; ++old)
for (int j = LDec + 1; j < i; ++j)
dp[i][nxt] += dp[j][old];
for (int old = nxt + 1; old < 26; ++old)
for (int j = LInc + 1; j < i; ++j)
dp[i][nxt] += dp[j][old];
}
}
Mint ret = 0;
for (int i = 0; i < longueur; ++i)
ret += accumulate(dp[i].begin(), dp[i].end(), Mint(0));
cout << ret << endl;
}
