import sys
from time import clock
f=open('in12_3.txt','r')
of=open('out_23_12_3.txt','w')
begin=clock()
m=[]
m=f.readline().split(' ')
last=len(m)
def gold(From,to,m):

    global reccall
    reccall+=1
    for i in range(0,len(m)):
        m[i]=int(m[i])
    
    mid=(From+to)/2
    if m[mid]<4:
        
        return mid
    sum12=0
    sum1=0
    for i in range(From,mid):
        sum12=sum12+m[i]
    
    for i in range(mid+1,to):
        sum1=sum1+m[i]
    
    if (sum12%4==0):
        ans=gold(mid+1,to,m)
        
        return ans
    if (sum1%4==0):
        ans=gold(From,mid,m)
        
        return ans

reccall=0
k=gold(0,len(m),m)
of.write(str(k+1)+"\n")
of.write("Number of recursive calls="+str(reccall)+"\n")
of.write("Memory used="+str(sys.getsizeof(f)+sys.getsizeof(of)+sys.getsizeof(last)+sys.getsizeof(begin)))
of.write("\n"+"time taken="+str(clock()-begin))
f.close()
of.close()