func_code_string: #include <bits/stdc++.h>   using namespace std;   template <typename A, typename B>   string to_string(pair<A, B> p);   template <typename A, typename B, typename C>   string to_string(tuple<A, B, C> p);   template <typename A, typename B, typename C, typename D>   string to_string(tuple<A, B, C, D> p);   string to_string(const string& s) { return     + s +    ; }   string to_string(const char* s) { return to_string((string)s); }   string to_string(bool b) { return (b ?  true  :  false ); }   string to_string(vector<bool> v) {     bool first = true;     string res =  { ;     for (int i = 0; i < static_cast<int>(v.size()); i++) {       if (!first) {         res +=  ,  ;       }       first = false;       res += to_string(v[i]);     }     res +=  } ;     return res;   }   template <size_t N>   string to_string(bitset<N> v) {     string res =   ;     for (size_t i = 0; i < N; i++) {       res += static_cast<char>( 0  + v[i]);     }     return res;   }   template <typename A>   string to_string(A v) {     bool first = true;     string res =  { ;     for (const auto& x : v) {       if (!first) {         res +=  ,  ;       }       first = false;       res += to_string(x);     }     res +=  } ;     return res;   }   template <typename A, typename B>   string to_string(pair<A, B> p) {     return  (  + to_string(p.first) +  ,   + to_string(p.second) +  ) ;   }   template <typename A, typename B, typename C>   string to_string(tuple<A, B, C> p) {     return  (  + to_string(get<0>(p)) +  ,   + to_string(get<1>(p)) +  ,   +            to_string(get<2>(p)) +  ) ;   }   template <typename A, typename B, typename C, typename D>   string to_string(tuple<A, B, C, D> p) {     return  (  + to_string(get<0>(p)) +  ,   + to_string(get<1>(p)) +  ,   +            to_string(get<2>(p)) +  ,   + to_string(get<3>(p)) +  ) ;   }   void debug_out() { cerr << endl; }   template <typename Head, typename... Tail>   void debug_out(Head H, Tail... T) {     cerr <<     << to_string(H);     debug_out(T...);   }   const int mod = 1e9 + 7;   const int maxn = 200005;   const int inf = 1e9;   int tiempo[maxn], x[maxn], y[maxn], pref[maxn], dp[maxn];   void solve() {     int r, n;     cin >> r >> n;     for (int i = 1; i <= n; i++) {       cin >> tiempo[i] >> x[i] >> y[i];       dp[i] = -inf;     }     x[0] = y[0] = 1;     int ans = -inf;     for (int i = 1; i <= n; i++) {       for (int j = i - 1; j >= 0; j--) {         if (tiempo[i] - tiempo[j] > 2 * r) {           dp[i] = max(dp[i], pref[j] + 1);           break;         }         int dist = abs(x[i] - x[j]) + abs(y[i] - y[j]);         if (dist <= (tiempo[i] - tiempo[j])) {           dp[i] = max(dp[i], dp[j] + 1);         }       }       pref[i] = pref[i - 1];       pref[i] = max(pref[i], dp[i]);       ans = max(ans, pref[i]);     }     cout << ans <<   n ;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int t = 1;     while (t--) {       solve();     }     return 0;   }   