a=[]
n=int(input())
for i in range(0,n):
    f=(int,input())
    a.append(f)
sum=0
ans=0
for i in range(0,n-2):
    sum=0
    for f in range(i,i+3):
        sum=sum+a[f]
    if(sum>ans):
       ans=sum
       z=f
print(ans)
print(z)


#What could be the error in this. It works on my computer. Why do they show runtime error #when submitted??

Because of the way you are getting input.
 http://ideone.com/COmKqT
Maybe on your machine you are pressing Enter before after each number.  Maybe your interpeter is smarter than mine.
You should write:
a=list (map (int, input (). split ()))

 a