//tnnd，怎么这么卡常
#include<bits/stdc++.h>
using namespace std;

int read(){
	int a = 0; char c = getchar(); while(!isdigit(c)) c = getchar();
	while(isdigit(c)){a = a * 10 + c - 48; c = getchar();} return a;
}

#define int long long
const int _ = 2e5 + 7 , __ = _ * 5; int N , A[_] , B[_] , C[_] , sum[3][_] , L1 , L2; vector < int > pot;
int findid(int x){return (--upper_bound(pot.begin() , pot.end() , x)) - pot.begin() + 1;}
struct segt{
#define lowbit(x) ((x) & -(x))
	signed sum[__] , rt; void clr(){memset(sum , 0 , sizeof(sum)); rt = 1;}
	void mdf(signed x , int l , int r , int t , int c = 1){while(t <= (int)pot.size() + 1){sum[t] += c; t += lowbit(t);}}
	int qry(int x , int l , int r , int L , int R){int all = 0; while(R){all += sum[R]; R -= lowbit(R);} return all;}
}Tree[3];

int Count(int mid){
	int num = 0 , mrk1 = 0 , mrk2 = 0;
	if(pot.empty()){
		for(int i = 1 ; i + L2 - 1 <= N ; ++i){
			pot.push_back(sum[0][i + L2 - 1] - sum[0][i - 1]);
			pot.push_back(sum[2][i + L2 - 1] - sum[2][i - 1]);
		}
		for(int i = L1 - L2 + 2 ; i <= L1 && i + L2 - 1 <= N ; ++i) pot.push_back(sum[2][L1] - sum[2][i - 1] + sum[0][i + L2 - 1] - sum[0][L1]);
		for(int i = 1 ; i + L1 - 1 <= N ; ++i){
			if(i + L1 + L2 - 1 <= N) pot.push_back(sum[0][i + L1 + L2 - 1] - sum[0][i + L1 - 1] - mrk2);
			mrk2 += C[i + L1] - 2 * B[i + L1]; pot.push_back(sum[2][i + L2 - 1] - sum[2][i - 1] - mrk1); mrk1 += 2 * B[i] - C[i];
		}
		sort(pot.begin() , pot.end()); pot.resize(unique(pot.begin() , pot.end()) - pot.begin());
	}
	
	mrk1 = mrk2 = 0; for(int i = 0 ; i < 3 ; ++i){Tree[i].clr();} 
	for(int i = 1 ; i <= L1 - L2 + 1 ; ++i) Tree[0].mdf(Tree[0].rt , 0 , pot.size() + 1 , findid(sum[2][i + L2 - 1] - sum[2][i - 1]));
	for(int i = L1 - L2 + 2 ; i <= L1 && i + L2 - 1 <= N ; ++i) Tree[2].mdf(Tree[2].rt , 0 , pot.size() + 1 , findid(sum[2][L1] - sum[2][i - 1] + sum[0][i + L2 - 1] - sum[0][L1]));
	for(int i = L1 + 1 ; i + L2 - 1 <= N ; ++i) Tree[0].mdf(Tree[0].rt , 0 , pot.size() + 1 , findid(sum[0][i + L2 - 1] - sum[0][i - 1]));
	for(int i = 1 ; i + L1 - 1 <= N ; ++i){
		num += Tree[0].qry(Tree[0].rt , 0 , pot.size() + 1 , 0 , findid(mid - sum[0][i + L1 - 1] + sum[0][i - 1])) +
			Tree[1].qry(Tree[1].rt , 0 , pot.size() + 1 , 0 , findid(mid - mrk1 - sum[0][i + L1 - 1] + sum[0][i - 1])) +
			Tree[2].qry(Tree[2].rt , 0 , pot.size() + 1 , 0 , findid(mid - mrk2 - sum[0][i + L1 - 1] + sum[0][i - 1]));
		if(i + L1 - 1 == N) continue;
		if(i + L1 + L2 - 1 <= N){
			Tree[0].mdf(Tree[0].rt , 0 , pot.size() + 1 , findid(sum[0][i + L1 + L2 - 1] - sum[0][i + L1 - 1]) , -1);
			Tree[2].mdf(Tree[2].rt , 0 , pot.size() + 1 , findid(sum[0][i + L1 + L2 - 1] - sum[0][i + L1 - 1] - mrk2));
		}
		mrk2 += C[i + L1] - 2 * B[i + L1];
		Tree[2].mdf(Tree[2].rt , 0 , pot.size() + 1 , findid(sum[2][i + L1] - sum[2][i + L1 - L2] - mrk2) , -1);
		Tree[0].mdf(Tree[0].rt , 0 , pot.size() + 1 , findid(sum[2][i + L1] - sum[2][i + L1 - L2]));
		Tree[0].mdf(Tree[0].rt , 0 , pot.size() + 1 , findid(sum[2][i + L2 - 1] - sum[2][i - 1]) , -1);
		Tree[1].mdf(Tree[1].rt , 0 , pot.size() + 1 , findid(sum[2][i + L2 - 1] - sum[2][i - 1] - mrk1));
		mrk1 += 2 * B[i] - C[i];
		if(i >= L2){
			Tree[1].mdf(Tree[1].rt , 0 , pot.size() + 1 , findid(sum[0][i] - sum[0][i - L2] - mrk1) , -1);
			Tree[0].mdf(Tree[0].rt , 0 , pot.size() + 1 , findid(sum[0][i] - sum[0][i - L2]));
		}
	}
	return num;
}

int check(int val , int L = 1 , int R = 2e14){
	while(L < R){
		int mid = (L + R) >> 1;
		Count(mid) >= val ? R = mid : L = mid + 1;
	} return L;}
double check1(int val){
	int L = 1 , R = 2e14;
	while(L < R){
		int mid = (L + R) >> 1 , C = Count(mid);
		if(C >= val + 1) R = mid; else if(C < val) L = mid + 1;
		else{int p = check(val , L , mid), q = check(val + 1 , mid + 1 , R); return (p + q) * 0.5;}
	}
	return L;
}

signed main(){
	N = read(); L1 = read(); L2 = read(); for(int i = 1 ; i <= N ; ++i){A[i] = read(); B[i] = read(); C[i] = read();}
	L1 = min(N, L1); L2 = min(N, L2); if(L1 < L2) swap(L1 , L2); int all = 0; for(int i = 1 ; i <= N ; ++i){all += A[i]; B[i] -= A[i]; C[i] -= A[i];} 
	for(int i = 1 ; i <= N ; ++i){sum[0][i] = sum[0][i - 1] + B[i]; sum[1][i] = sum[1][i - 1] + C[i]; sum[2][i] = sum[1][i] - sum[0][i];}
	int num = Count(1e15); if(num & 1) cout << check(num / 2 + 1) + all << ".0"; else cout << fixed << setprecision(1) << check1(num / 2) + all;
	return 0;
}