#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <cstdio>
#include <cstring>
#include <set>
#include <map>
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
#define F first
#define S second
double x[15],y[15],w[15],dp[15][1<<15],s;
int n;
int main(void){
    cin>>x[0]>>y[0]>>n;
    n++;
    for(int i=1;i<n;i++)cin>>x[i]>>y[i]>>w[i];
    for(int i=0;i<n;i++)for(int j=0;j<1<<n;j++)dp[i][j]=500000;
    dp[0][0]=0;
    for(int k=0;k<1<<n;k++){
        s=0;
        for(int i=1;i<n;i++)if(!(k>>i&1))s+=w[i];
        for(int p=0;p<n;p++){
        for(int i=0;i<n;i++){
            if(!(k>>i&1)){
                dp[i][k|1<<i]=min(dp[i][k|1<<i],dp[p][k]+(abs(x[p]-x[i])+abs(y[p]-y[i]))*(s+100)/120+w[i]);
            }
        }
        }
    }
    cout<<dp[0][(1<<n)-1]<<endl;
}