02b-red-nosed-reports.cpp

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#ifdef _DEBUG
#include "utils/debug.h"
#else
#define debug(...)
#endif

int main() {
	cin.tie(0)->sync_with_stdio(0);
	string line;
	ll ans = 0;
	auto safe = [&](vector<int> v) -> bool {
		vector<int> f = v;
		vector<int> r = v;
		sort(f.begin(), f.end());
		sort(r.begin(), r.end(), greater<int>());
		if (v != f && v != r) return 0;
		bool ok = 1;
		for (int i = 1; i < (int)v.size(); ++i) {
			ok &= abs(v[i] - v[i-1]) <= 3 && abs(v[i] - v[i-1]) > 0;
		}
		return ok;
	};

	while (getline(cin, line)) {
		istringstream iss(line);
		vector<int> v;
		int x;
		while (iss >> x) v.push_back(x);
		if (safe(v)) {
			ans++;
			continue;
		}
		for (int i = 0; i < (int)v.size(); ++i) {
			auto cur = v;
			cur.erase(cur.begin() + i);
			if (safe(cur)) {
				ans++;
				break;
			}
		}
	}
	cout << ans << '\n';
}