1 #include <iostream>
2 #include <vector>
3
4 using namespace std;
5
6 int main(){
7 int m,sum = 0;
8 cin >> m ;
9 vector<int> c(m+1,0);
10 for(int i = 1; i <= m ; ++ i) {cin >> c[i];sum+=c[i];}
11 int x,y,firstPart = 0, secondPart = 0,firstIndex = 0, secondIndex =0;
12 cin >> x >> y;
13 for(firstIndex = 0,secondIndex = m+1;firstIndex < secondIndex;){
14 if (firstPart < x) firstPart+=c[++firstIndex];
15 if (secondPart < x) secondPart += c[--secondIndex];
16 if( firstPart >= x && secondPart >= x ) break;
17 }
18 if(firstPart > y || secondPart > y) cout<<0<<endl;
19 else{
20 if(firstIndex >= secondIndex) cout<<0<<endl;
21 else{
22 if(sum - firstPart - secondPart > 2*(y-x)) cout<<0<<endl;
23 else{
24 while(secondPart + c[secondIndex-1]<= y && (secondIndex-1) > firstIndex){
25 secondIndex--;
26 secondPart+=c[secondIndex];
27 }
28 if (secondIndex-1 <= firstIndex) cout<<secondIndex<<endl;
29 else{
30 if(sum - secondPart > y) cout<<0<<endl;
31 else cout<<secondIndex<<endl;
32 }
33 }
34 }
35 }
36 }