#include <bits/stdc++.h>

using namespace std;

const int oo = 0x3f3f3f3f;
const double eps = 1e-9;
const double PI = 2.0 * acos(0.0);


typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<string> vs;

#define sz(c) int((c).size())
#define all(c) (c).begin(), (c).end()
#define FOR(i,a,b) for (int i = (a); i < (b); i++)
#define FORS(i,a,b,s) for (int i = (a); i < (b); i=i+(s))
#define FORD(i,a,b) for (int i = int(b)-1; i >= (a); i--)
#define FORIT(i,c) for (__typeof__((c).begin()) i = (c).begin(); i != (c).end(); i++)


int s[3000];
int ep[3000];
int eu[3000];
int st[3000];

vector<pii> exSt;

int dp[3000][3000];

int main(){
	int n; cin >> n;
	eu[0] = 0;
	FOR(i,1,n+1){
		cin >> s[i] >> ep[i] >> eu[i] >> st[i];
	}

	// number of exams, number of passed exams, maximum number of time available.
	FOR(i,0,n+3)
		FOR(j,0,n+2)
			dp[i][j] = -oo;
	dp[0][0] = 0;


	int mm = 0;
	FOR(i,1,n+1) {
		dp[i][0] = eu[i]; // bug! But works in all samples ...
		FOR(j,1,i+2){
			int nt = s[i] - eu[i-1];
			// base option is not to study for i, which gives us more time

			dp[i][j] = dp[i-1][j] + nt;

			// actually to the exam
			if (dp[i-1][j-1] + nt >= st[i]){
				nt -= st[i];
				nt += eu[i] - ep[i];
				if (dp[i-1][j-1] + nt > dp[i-1][j])
					dp[i][j] = dp[i-1][j-1] + nt;
			}

			if (dp[i][j] >= 0 && j > mm)
				mm = j;
		}
	}

	cout << mm << endl;
}