F.cpp

// LUOGU_RID: 160487411
#include<bits/stdc++.h>
using namespace std;
int n, b, q;
vector<pair<int, int>>v;
int main() {
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	cin >> n >> b >> q;
	for (int i = 1; i <= q; i++) {
		int x, y; cin >> x >> y;
		v.push_back({ x,y });
	}
	v.push_back({ b,n });
	sort(v.begin(), v.end());
	for (int i = 0; i < v.size() - 1; i++)
		if (v[i].second > v[i + 1].second)
			return puts("unfair");
	for (int k = 0; k < 32; k++) {
		int can = 0;
		for (int i = 0; i <= q; i++) {
			int pre = i ? v[i - 1].first + 1 : 1, quan = i ? v[i].second - v[i - 1].second : v[i].second, s = 0;
			for (int j = pre; j <= v[i].first; j++)
				if ((k >> (j % 5)) & 1) s++;
			can += min(quan, s);
		}
		if (can < n / 5 * __builtin_popcount(k))
			puts("unfair"), exit(0);
	}
	puts("fair");
}