#include <stdio.h> #include <bits/stdc++.h> #include <atcoder/all> using namespace atcoder; using mint = modint1000000007; using namespace std; #define rep(i,n) for (int i = 0; i < (n); ++i) #define Inf 1000000000000000000 int main(){ vector<double> x(1),y(1),w(1); cin>>x[0]>>y[0]; w[0] = 0.0; int n; cin>>n; x.resize(n+1),y.resize(n+1),w.resize(n+1); double S = 0.0; rep(i,n){ cin>>x[i+1]>>y[i+1]>>w[i+1]; S += w[i+1]; } n++; vector dp(1<<n,vector<double>(n,1e30)); dp[0][0] = 0.0; rep(i,1<<n){ rep(j,n){ if(dp[i][j]>1e20)continue; double W = S; rep(k,n){ if((i>>k)&1)W -= w[k]; } rep(k,n){ if((i>>k)&1)continue; int ni = i | (1<<k); int nj = k; double nv = dp[i][j]; nv += (W+100.0)/120.0 * (abs(x[k]-x[j]) + abs(y[k]-y[j])); dp[ni][nj] = min(dp[ni][nj],nv); } } } double ans = dp.back()[0]; ans += S; cout<<fixed<<setprecision(10)<<ans<<endl; return 0; }