# Uses python3
import array as arr

def summ(ara,t):
    s=0
    for i in range (0,t):
        s=s+ara[i]
    return s

def fiboH(n):
    ar=arr.array('L',[0])
    ar.append(1)
    p=-1
    a=0
    b=1
    for i in range (2,n+1):
        c=b+a
        a=b
        b=c
        ar.append(c%10)
        if((ar[i-1]==0) & (ar[i]==1)):
            p=i-1
            break
    if(p!=-1):
        print((summ(ar,p)*(n//p) + summ(ar,n%p+1))%10)
    else:
        print((summ(ar,n+1))%10)
    
    
    
if __name__== "__main__":
    a=int(input())
    (fiboH(a))