force = [
    [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]
]

seq = list(map(int, input().split()))
n = len(seq)
inf = float("inf")
dp = [[[inf]*5 for _ in range(5)] for _ in range(2)]
for i in range(5) :
    for j in range(5) :
        dp[1][i][j] = 0

cur_idx = 0
nxt_idx = 1

for step in range(n-1,-1, -1) :
    target = seq[step]
    if target == 0 :
        continue
    
    for l in range(5) :
        for r in range(5) :
            moveLeft = dp[nxt_idx][target][r] + force[l][target]
            moveRight = dp[nxt_idx][l][target] + force[r][target]
            dp[cur_idx][l][r] = min(moveLeft, moveRight)
    
    cur_idx = 1 if cur_idx == 0 else 0
    nxt_idx = 1 if cur_idx == 0 else 0

print(dp[nxt_idx][0][0])