if let input = readLine(),
   let seq = input.split(separator: " ").compactMap({Int($0)}) as? [Int]
{
    let force: [[Int]] = [
        [1,2,2,2,2],
        [2,1,3,4,3],
        [2,3,1,3,4],
        [2,4,3,1,3],
        [2,3,4,3,1]
    ]
    
    var dp: [[[Int]]] = Array(repeating: Array(repeating: Array(repeating: 0, count: 5), count: 5), count: seq.count-1)
    
    func solve(_ step: Int, _ l: Int, _ r: Int) -> Int {
        if step == seq.count-1 { return 0 }
        
        if dp[step][l][r] != 0 { return dp[step][l][r] }
        
        let target = seq[step]
        
        let moveLeftCost = solve(step + 1, target, r) + force[l][target]
        let moveRightCost = solve(step + 1, l, target) + force[r][target]
        
        dp[step][l][r] = min(moveLeftCost, moveRightCost)
        
        return dp[step][l][r]
    }
    
    print(solve(0, 0, 0))
}