p, q, r, k = map(int, input().split())
M = [[1, 1, 1],[1, 2, 2],[2, 3, 4]]
mod = 10

def matmul(A, B):
    Ah, Bh, Bw = len(A), len(B), len(B[0])
    C = [[0 for _ in range(Bw)] for _ in range(Ah)]
    for i in range(Ah):
        for j in range(Bw):
            for k in range(Bh):
                C[i][j] += A[i][k] * B[k][j]
                C[i][j] %= mod
    return C

# Mのk乗を効率的に計算する
def doubling(M, k):
    k -= 1
    Mc = M.copy()
    while k > 0:
        if k & 1 == 1:
            Mc = matmul(Mc, M)
        M = matmul(M, M) # Mの(2のi乗)の乗 を計算する
        k >>= 1
    return Mc

qu, res = divmod(k - 1, 3)
Mt = doubling(M, qu)
ans = [0, 0, 0]
F = [p, q, r]
for i in range(3):
    for j in range(3):
        ans[i] += Mt[i][j] * F[j]
        ans[i] %= mod
print(ans[res])