1 #include <iostream>
 2 #include <queue>
 3 #include <stack>
 4 #include <cstdio>
 5 #include <vector>
 6 #include <map>
 7 #include <set>
 8 #include <bitset>
 9 #include <algorithm>
10 #include <cmath>
11 #include <cstring>
12 #include <cstdlib>
13 #include <string>
14 #include <sstream>
15 #include <time.h>
16 #define x first
17 #define y second
18 #define pb push_back
19 #define mp make_pair
20 #define lson l,m,rt*2
21 #define rson m+1,r,rt*2+1
22 #define mt(A,B) memset(A,B,sizeof(A))
23 #define mod 1000000007
24 using namespace std;
25 typedef long long LL;
26 const int N=2e5+10;
27 const int inf = 0x3f3f3f3f;
28 const LL INF=0x3f3f3f3f3f3f3f3fLL;
29 int x[N];
30 int n,a,b,ans,res_2=inf;
31
32
33 void dfs(int cur,int num)
34 {
35     int p=0,q;
36     if(cur==n-1)
37     {
38         ans=min(ans,num);
39         return;
40     }
41     if(x[cur-1]<0)dfs(cur+1,num);
42
43     if(x[cur-1]>=0)
44     {
45         p=x[cur-1]/b+1;
46         x[cur-1]-=p*b;
47         x[cur]-=p*a;
48         x[cur+1]-=p*b;
49         dfs(cur+1,num+p);
50         x[cur-1]+=p*b;
51         x[cur]+=p*a;
52         x[cur+1]+=p*b;
53     }
54     q=x[cur]/a+1;
55     if(x[cur]>=0&&q>p)
56     {
57         for(int i=p+1;i<=q;i++)
58         {
59             x[cur-1]-=i*b;
60             x[cur]-=i*a;
61             x[cur+1]-=i*b;
62             dfs(cur+1,num+i);
63             x[cur]+=i*a;
64             x[cur+1]+=i*b;
65             x[cur-1]+=i*b;
66         }
67     }
68 }
69 int main()
70 {
71 #ifdef Local
72     freopen("data.txt","r",stdin);
73 #endif
74     int p=0,q=0;
75     cin>>n>>a>>b;
76     ans=inf;
77     for(int i=0; i<n; i++)scanf("%d",&x[i]);
78     p=x[0]/b+1;
79     x[0]-=p*b;;
80     x[1]-=p*a;
81     x[2]-=p*b;
82     if(x[n-1]>=0)
83     {
84         q=x[n-1]/b+1;
85         x[n-2]-=q*a;
86         x[n-3]-=q*b;
87         x[n-1]-=q*b;
88     }
89     dfs(1,0);
90     if(ans==inf)ans=0;
91     cout<<ans+p+q<<endl;
92 #ifdef Local
93     cerr << "time: " << (LL) clock() * 1000 / CLOCKS_PER_SEC << " ms" << endl;
94 #endif
95 }