#include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #include <immintrin.h> #ifndef DEBUG //#pragma GCC optimize("O3") //#pragma GCC target("avx2") #endif using namespace __gnu_pbds; using namespace __gnu_cxx; using namespace std; // using ld = long double; using ll = long long; using i128 = __int128; using ull = unsigned long long; using pll = std::pair<ll, ll>; using cmpl = std::complex<ld>; template<typename T> using oset = tree<T, null_type, std::less<T>, rb_tree_tag, tree_order_statistics_node_update>; constexpr ll MOD1 = 998244353; constexpr ll MOD = 1000000007; constexpr ll INV2 = 499122177; constexpr ld PI = 3.141592653589793; const ld eps = 1e-7; const ll K = 3; //const ll C = 200; std::mt19937 rnd(std::chrono::steady_clock::now().time_since_epoch().count()); ld START_TIME = clock(); bool cmp(pll a, pll b){ return (a.first - a.second) > (b.first - b.second) || ((a.first + a.second) > (b.first + b.second)); } void solve() { ll n; std::cin >> n; std::vector<pll> a(n); for (int i = 0; i < n; ++i) { std::cin >> a[i].first >> a[i].second; } std::sort(a.begin(), a.end(), cmp); ll ans = 0; std::vector<ll> used(n); std::vector<pll> bb; ll max = -1; for (int i = 0; i < n; ++i) { if (a[i].second + a[i].first > max){ max = std::max(max, a[i].second + a[i].first); ++ans; } } std::cout << ans; } signed main() { #ifdef DEBUG std::freopen("/home/anton/CLionProjects/untitled/input.txt", "r", stdin); #else // std::freopen("tri.in", "r", stdin); std::freopen("tri.out", "w", stdout); #endif // std::cin.tie(nullptr)->std::ios_base::sync_with_stdio(false); int tt = 1; // std::cin >> tt; while (tt--) { solve(); } #ifdef DEBUG std::cerr << '\n'; ld TIME = (clock() - START_TIME) / CLOCKS_PER_SEC; std::cerr << "Time: " << TIME << '\n'; #endif }