oj里的一道题，wrong answer,想知道哪里出现错误了

[xuanmaihenmang]

#include <iostream>
using namespace std;
int S1[1000];
int S2[1000];
int main()
{
int N,time;
cin>>N;
int record=0;
while(N)
{
time=N*5;
for(int i=0;i<N;i++)
{
cin>>S1[i];
}
for(int i=0;i<N;i++)
{
if(S1[i]>S1[i+1])
{
if(i==0&&S1[i+1]!=0){time+=S1[i]*6+(S1[i]-S1[i+1])*4;}
if(i==0&&S1[i+1]==0){time+=S1[i]*6;}
else{time+=(S1[i]-S1[i+1])*4;}
}
if(S1[i]<S1[i+1])
{
if(i==0){time+=S1[i]*6+(S1[i+1]-S1[i])*6;}
else{time+=(S1[i+1]-S1[i])*6;}
}

}
S2[record]=time;
record++,time=0;
cin>>N;
}
for(int i=0;i<record;i++)
cout<<S2[i]<<endl;
return 0;
}