#include<cstdio>

#include<iostream>

#include<cstring>

using namespace std;

int n,k;

struct matrix

{

    double m[][];

}temp,ans;

matrix mul(matrix a,matrix b)

{

    matrix c;

    for(int i=;i<n;i++)

        for(int j=;j<n;j++)

    {

         c.m[i][j]=;

        for(int q=;q<n;q++)

            c.m[i][j]=c.m[i][j]+ a.m[i][q]*b.m[q][j];

    }

    return c;

}

void fast(void)

{

    memset(ans.m,,sizeof(ans.m));

    for(int i=;i<n;i++)ans.m[i][i]=;

    while(k)

    {

        if(k&)ans=mul(ans,temp);

        temp=mul(temp,temp);

        k>>=;

    }

    return ;

}

int main()

{

    while(scanf("%d%d",&n,&k)==&&n&&k)

    {

        memset(temp.m,,sizeof(temp.m));

        for(int i=;i<n;i++)temp.m[i][i]=;

        int t[]={};

        for(int i=;i<n;i++)scanf("%d",&t[i]);

        int q;

        scanf("%d",&q);

        while(q--)

        {

            int x,y;double z;

            scanf("%d%d%lf",&x,&y,&z);

            temp.m[x][x]-=z;

            temp.m[x][y]+=z;

        }

         fast();

         double sum=;

         for(int i=;i<n;i++)sum+=t[i]*ans.m[i][n-];

         printf("%.0f\n",sum);

    }

}