#include <iostream>#include <algorithm>#include <string.h>#include <cstdio>using namespace std;typedef long long ll;const ll maxv=1e18;ll dp[2][5][5];void inti(int now){     for(int i=0; i<5; ++i)        for(int j=0; j<5; ++j)       dp[now][i][j]=maxv;}ll cal(int a, int b){     if( a==0 || b==0 ) return 2;     if( a == b ) return 1;     int t1 = a+1 ;     if( t1 > 4 )  t1=1;     if( t1 == b ) return 3;     t1 = a-1;     if( t1 < 1 )  t1=4;     if( t1 == b ) return 3;     return 4;}int main(){     int n;     while(scanf("%d",&n)==1&&n){          int now=0;          int late=1;          inti(0);          dp[0][0][n]=2;          dp[0][n][0]=2;          int per=n;          while(true){              scanf("%d",&n);              if(n==0) break;              per=n;              now=1-now;              late=1-late;              inti(now);              for(int i=0; i<5; ++i)                for(int j=0; j<5; ++j){                       if(i==j||i==n)continue;                      dp[now][n][i] = min(dp[late][j][i]+cal(j,n),dp[now][n][i]);                }              for(int i=0; i<5; ++i)              for(int j=0; j<5; ++j){                  if(i==j||i==n) continue;                  dp[now][i][n]=min( dp[now][i][n] , dp[late][i][j]+cal(j,n) );              }          }          ll ans=maxv;          for(int i=0;i<5 ; ++i)            ans=min(ans, min( dp[now][per][i],dp[now][i][per]));          printf("%lld\n",ans);     }    return 0;}