#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld double
#define pii pair<int,int>
#define vi vector<int>
#define si set<int>
#define unsi unordered_set<int>
#define qi queue<int>
#define sti stack<int>
#define pqi priority_queue<int>
#define mii map<int,int>
#define unmii unordered_map<int,int>
#define fi first
#define se second
#define pb push_back
#define clr(f,n) memset(f,0,sizeof(int)*(n))
#define cpy(f,g,n) memcpy(f,g,sizeof(int)*(n))
const int N=5000000+5;
struct sdf{
    ld x,y,k;
}p[N];
int n;
ld m,f[N],vv[N];
int q[N],id[N],tmp[N],tp=0;
vi b;
inline ld slope(int i,int j){
    return (f[j]-p[j].y-f[i]+p[i].y)/(p[j].x-p[i].x);
}
void cdq(int l,int r){
    if (l==r)return ;
    int mid=(l+r)/2;
    cdq(l,mid);tp=0;
    for (int i=l;i<=mid;i++){
        while(tp>1&&slope(q[tp-1],q[tp])>=slope(q[tp],id[i]))q[tp--]=0;
        q[++tp]=id[i];
    }
    for (int i=mid+1,st=tp;i<=r;i++){
        while(st>1&&slope(q[st-1],q[st])>p[i].k)st--;
        int j=q[st];
        f[i]=min(f[i],-p[i].k*p[j].x-p[j].y+f[j]+vv[i]);
    }
    cdq(mid+1,r);
    for (int k=l,i=l,j=mid+1;k<=r;k++){
        if (j>r||(i<=mid&&p[id[i]].x<p[id[j]].x))tmp[k]=id[i++];
        else tmp[k]=id[j++];
    }
    for (int i=l;i<=r;i++)id[i]=tmp[i];
}
inline ld read(){
    ll ans=0;char ch=getchar();
    while(!isdigit(ch))ch=getchar();
    while(isdigit(ch))ans=(ans<<1)+(ans<<3)+(ch^48),ch=getchar();
    return ans;
}
int main(){
	freopen ("2012sdoi_jzjs.in","r",stdin);
	freopen ("2012sdoi_jzjs.out","w",stdout);
	scanf("%d%lf",&n,&m);
	for (int i=1;i<=n;i++){
	    ld x=read(),r=read(),v=read();
	    if (abs(m-x)<=r)b.pb(i);
	    r=sqrt(r);id[i]=i;
	    p[i].x=1.0/r;p[i].y=x/(2.0*r);p[i].k=-x/2;
	    f[i]=1e18;vv[i]=v;
    }
    f[1]=vv[1];
    cdq(1,n);
    ld ans=1e18;
    for (int i=0;i<b.size();i++)ans=min(ans,f[b[i]]);
    printf("%.3lf\n",ans);
}