//#include #include #include #include #include #include #include #include #include #include #include #include #define rep(i,n) for(int i = 0; i < n; i++) //[0,n) #define srep(i,a,b) for(int i = a; i < b; i++) //[a,b) #define arep(i,a,b,d) for(int i = a; i < b; i += d) #define all(A) (A).begin(),(A).end() #define rall(A) (A).rbegin(),(A).rend() #define pmt(A) next_permutation(all(A)) using namespace std; using ll = long long; using ull = unsigned long long; using pq = priority_queue,greater>; const ll inf = 1LL<<60; const int iinf = (int)1e9+1; const int mod9 = 998244353; const int mod1 = (int)1e9+7; struct Edge { int to; long long cost; int from; }; bool compe(const Edge &e,const Edge &e2){ return e.cost < e2.cost; } using Graph = vector>; using SGraph = vector>; template int siz(T& a){return (int)a.size();} ll squa(ll a){ return a*a; } double torad(double x){ return x*(acos(-1)/180.0); } ll cross(ll ax,ll ay,ll bx,ll by){ return ax*by-ay*bx; } ll mceil(ll a,ll b){ return (a+b-1)/b; } ll dp[5001][15001]; int main(){ int N,P; cin >> N >> P; vector a(N),b(N),c(N); rep(i,N) cin >> a[i] >> b[i] >> c[i]; rep(i,5001) rep(j,15001) dp[i][j] = iinf; dp[0][0] = 0; rep(i,N){ rep(j,P+1){ rep(k,4){ if(j-k < 0) continue; int add = 0; if(k == 0) add = a[i]; if(k == 1) add = b[i]; if(k == 2) add = c[i]; if(k == 3) add = 1; dp[i+1][j] = min(dp[i+1][j],dp[i][j-k]+add); } } } cout << fixed << setprecision(10) << 1.0*dp[N][P]/N; }