# Uses python3
import sys
def getFibLastDigitNaive(n):
    if n <= 1:
        return n
 
    previous = 0
    current  = 1
 
    for _ in range(n - 1):
        previous, current = current, previous + current
 
    return current % 10


def getFibLastDigitOptimized(n):
    if (n <= 1):
        return n
    fibLst = [None] * (n+1)
    fibLst[0] = 0
    fibLst[1] = 1
    for i in range(2, n+1):
        fibLst[i] = (fibLst[i-1] + fibLst[i-2]) % 10
    return fibLst[n]

if __name__ == '__main__':
    input = sys.stdin.read()
    n = int(input)
    print(getFibLastDigitOptimized(n))