export {};
const inst: number[] = require("fs").readFileSync(0).toString().trim().split(" ").map(Number);
const steps: number = inst.length - 1;

const force: number[][] = [
    [1,2,2,2,2],
    [0,1,3,4,3],
    [0,3,1,3,4],
    [0,4,3,1,3],
    [0,3,4,3,1]
];

let dp: number[][][] = Array.from({length: inst.length-1}, () => Array.from({length: 5}, () => new Array(5).fill(0)));

const solve = (step: number, left: number, right: number): number => {
    if (step === steps) return 0;

    if (dp[step][left][right] === 0) {
        const next: number = inst[step];
        dp[step][left][right] = Math.min(
            solve(step+1, next, right) + force[left][next],
            solve(step+1, left, next) + force[right][next]
        );
    };

    return dp[step][left][right];
};

console.log(solve(0,0,0));