import java.text.DecimalFormat;
import java.util.*;

public class Main {
    public static double max(double[] array) {
        double result = Double.MIN_VALUE;
        for(int i = 0; i < array.length; i++) {
            if(array[i] > result) {
                result = array[i];
            }
        }
        return result;
    }

    public static int argmax(double[] array) {
        int result = 0;
        double maxValue = Double.MIN_VALUE;
        for(int i = 0; i < array.length; i++) {
            if(array[i] > maxValue) {
                maxValue = array[i];
                result = i;
            }
        }
        return result;
    }

    public static void main(String[] args) throws IOException {
        Scanner in = new Scanner(System.in);

        while(in.hasNext()) {
            double[] pi = new double[4];
            double[][] A = new double[4][4];
            double[][] B = new double[4][5];

            double prob = 0.0;
            for(int i = 0; i < 4; i++)
                pi[i] = in.nextDouble();

            for(int i = 0; i < 4; i++) {
                for (int j = 0; j < 4; j++)
                    A[i][j] = in.nextDouble();
            }

            for(int i = 0; i < 4; i++) {
                for (int j = 0; j < 5; j++)
                    B[i][j] = in.nextDouble();
            }

            String a = in.next();
            String line = in.nextLine();
            line = a + line;
            String[] o = line.split(" ");
            int[] observe = new int[o.length];
            for(int i = 0; i < o.length; i++) {
                if(o[i].equals("S"))
                    observe[i] = 0;
                else if(o[i].equals("A"))
                    observe[i] = 1;
                else if(o[i].equals("B"))
                    observe[i] = 2;
                else if(o[i].equals("C"))
                    observe[i] = 3;
                else
                    observe[i] = 4;
            }

            double[][] x = new double[observe.length][4];

            int T = observe.length;

            for(int i = 0; i < 4; i++) {
                x[0][i] = pi[i] * B[i][observe[0]];
            }


            for(int t = 1; t < T; t++) {
                for(int i = 0; i < 4; i++) {
                    double tmp = 0.0;
                    for(int j = 0; j < 4; j++) {
                        tmp += x[t - 1][j] * A[j][i];
                    }
                    x[t][i] = tmp * B[i][observe[t]];
                }
            }

            prob = x[T - 1][0] + x[T - 1][1] + x[T - 1][2] + x[T - 1][3];
            DecimalFormat df = new DecimalFormat("#.0000");
            System.out.println(df.format(Math.log10(prob)));
        }
    }
}

一开始没看清题，写成了Viterbi，浪费了半个多小时，吐血