n = int(input())
a = list(map(int, input().split()))
best = 2 if n > 1 else 1
current = 2
if n>2:
for i in range(2,n):
if a[i]==a[i-1]+a[i-2]:
current += 1
else:
best = max(best,current)
current = 2
best = max(best,current)
print(best)#include<bits/stdc++.h>
using namespace std;
int main(){
int n;
cin >> n;
vector<int> nums;
for(int i = 0;i<n;i++){
int x;
cin >> x;
nums.push_back(x);
}
int count = 2;
int maxn = 0;
for(int i = 2;i<n;i++){
if(nums[i]==nums[i-1]+nums[i-2]){
count+=1;
}
else{
maxn = max(count,maxn);
count = 2;
}
}
maxn = max(count,maxn);
if(n==1){
maxn = 1;
}
cout << maxn << endl;
}1519A - Red and Blue Beans | 466A - Cheap Travel |
659E - New Reform | 1385B - Restore the Permutation by Merger |
706A - Beru-taxi | 686A - Free Ice Cream |
1358D - The Best Vacation | 1620B - Triangles on a Rectangle |
999C - Alphabetic Removals | 1634C - OKEA |
1368C - Even Picture | 1505F - Math |
1473A - Replacing Elements | 959A - Mahmoud and Ehab and the even-odd game |
78B - Easter Eggs | 1455B - Jumps |
1225C - p-binary | 1525D - Armchairs |
1257A - Two Rival Students | 1415A - Prison Break |
1271A - Suits | 259B - Little Elephant and Magic Square |
1389A - LCM Problem | 778A - String Game |
1382A - Common Subsequence | 1512D - Corrupted Array |
667B - Coat of Anticubism | 284B - Cows and Poker Game |
1666D - Deletive Editing | 1433D - Districts Connection |