#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <cmath>

using namespace std;
const int N = 30,M = 30;
const int V = 3*N*M;
const double eps = 1e-9;

bool cmp(int a,int b) {return a>b;}
struct edge{
  double cap,flow;
  int to, r_edge;
  edge() {}
  edge(int _to, double _c, int _r ):
    cap(_c), flow(0), to(_to), r_edge(_r) {}
};

int n, m, p[N], r[N], d[N], s[M], W;

int nv;
vector<edge> g[10000];
int addV() {g[nv].clear(); return nv++; }
void addE(int a,int b, double cap){
    g[a].push_back(edge(b, cap, g[b].size()));
    g[b].push_back(edge(a, 0, g[a].size()-1));
}

int start, target;
vector<char> used(V);
bool dfs(int v,double d){
    if(v == target) return true;
    used[v]=1;
    int sz=g[v].size();
    for (int i=0;i<sz;i++){
        edge &e = g[v][i];
        int u=e.to,r=e.r_edge;
        if(e.flow + d <= e.cap && !used[u] && dfs(u,d)){
            e.flow += d, g[u][r].flow -= d;
            return true;
        }
    }
    return false;
}
double maxFlow(){
    double d = 1.0e6, sum=0;
    for(int i=0;i<40;i++,d /= 2)
        while(true){
            used.assign(sizeof(used),0);
            if(!dfs(start,d)) break;
            sum += d;
        }
  return sum;
}

bool check( double add ){
    nv=0;
    start=addV();
    target=addV();
    int cheeze=nv;
    for(int i=0;i<n;i++)
    addE(addV(),target,(double)p[i]);
    vector<double> ti;
    for(int i=0;i<n;i++){
        ti.push_back((double)r[i]);
        ti.push_back(d[i] + add);
    }
    sort(ti.begin(),ti.end());
    ti.resize(unique(ti.begin(), ti.end()) - ti.begin());
    for(int i=1;i<(int)ti.size();i++){
        double dt=ti[i]-ti[i-1];
        int vc = nv;
        for(int j=0;j<m;j++)
            addE(start,addV(),dt*s[j]*(j+1));
        for(int j=0;j<m;j++)
            for(int k=0;k<n;k++)
                if((r[k]-eps <= ti[i-1]) && (ti[i] <= d[k]+add+eps))
                    addE(vc+j,cheeze+k,dt*s[j]);
        }
  return fabs(maxFlow() - W) < eps;
}

int main(){
    scanf("%d%d", &n, &m);
    for(int i=0;i<n;i++){
        scanf("%d%d%d",p+i,r+i,d+i);
        W += p[i];
    }
    for(int i=0;i<m;i++)
        scanf("%d",s+i);
    sort(s,s+m,cmp);
    for(int i=0;i < m-1;i++)
        s[i] -= s[i+1];
    double l=0,r=1.0e9;
    while(r-l<eps){
        double mid=(l+r)/2;
        if(check(mid)) r=mid;
        else l=mid;
    }
    printf("%.7lf\n",l);
}