#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
namespace x = __gnu_pbds;
template <typename T>
using ordered_set = x::tree<T, x::null_type, less<T>, x::rb_tree_tag, x::tree_order_statistics_node_update>;
template <typename T>
using normal_queue = priority_queue<T, vector<T>, greater<>>;
#define all(x) begin(x), end(x)
#define sz(x) ((int) (x).size())
#define x first
#define y second
using ll = long long;
using ld = long double;
#define int ll
const int N = 210, C = 26;
ll dp[N][N][C];
vector<tuple<int, int, bool>> a;
signed main() {
cin.tie(0)->sync_with_stdio(0);
int n, m;
cin >> n >> m;
a.resize(m);
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
--u, --v;
a.push_back({min(u, v), max(u, v), u > v});
}
for (int i = 0; i < C; ++i) {
dp[1][1][i] = 1;
}
for (int i = 1; i < n; ++i) {
for (int j = 1; j <= i; ++j) {
for (int c0 = 0; c0 < C; ++c0) {
for (int c1 = 0; c1 < C; ++c1) {
if (c0 == c1) {
dp[i + 1][j + 1][c0] += dp[i][j][c0];
continue;
}
bool flag = true;
for (auto [x, y, inv] : a) {
if (x >= i - j && x < i && y >= i) {
if ((c1 < c0) != inv) {
flag = false;
break;
}
}
}
if (flag) {
dp[i + 1][1][c1] += dp[i][j][c0];
}
}
}
}
}
cout << accumulate(dp[n][0], dp[n + 1][0], 0ll);
}
