########関数部分##############
def Base_n_to_10(X,n):
    out = 0
    for i in range(len(X)):
        x = X[i]
        out += x*(n**i)
    return out#int out
############################

N,K = map(int,input().split())
A = list(map(int,input().split()))
sumA = sum(A)
A.reverse()
numA = Base_n_to_10(A,K)

print(numA%sumA)