import java.util.*;

public class _2342 {
    static int INF = Integer.MAX_VALUE;
    static int[][] move_energy = {
        {0,2,2,2,2},
        {0,1,3,4,3},
        {0,3,1,3,4},
        {0,4,3,1,3},
        {0,3,4,3,1}
    };
    static int[][][] dp = new int[2][5][5];
    static int curr = 0, next = 1;

    static void swap() {
        int temp = curr;
        curr = next;
        next = temp;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[] inst = Arrays.stream(sc.nextLine().split(" "))
                           .mapToInt(Integer::parseInt)
                           .toArray();
        sc.close();

        for(int i=0; i<2; i++) {
            for(int l=0; l<5; l++) {
                for(int r=0; r<5; r++) {
                    if(i==0) dp[i][l][r] = INF;
                    else dp[i][l][r] = 0;
                }
            }
        }

        for(int i=inst.length-2; i>=0; i--) {
            int target = inst[i];
            for(int L=0; L<5; L++) {
                for(int R=0; R<5; R++) {
                    int moveLeft = dp[next][target][R] + move_energy[L][target];
                    int moveRight = dp[next][L][target] + move_energy[R][target];

                    dp[curr][L][R] = Math.min(moveLeft, moveRight);
                }
            }
            swap();
        }

        System.out.println(dp[next][0][0]);
    }
}