import sys

sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = 18446744073709551615
# inf = 4294967295
# md = 10**9+7
# md = 998244353
md = 10**8+9

def dot(aa, bb):
    h = len(aa)
    w = len(bb[0])
    res = [[0]*w for _ in range(h)]
    for i, row in enumerate(aa):
        for j, col in enumerate(zip(*bb)):
            v = -inf
            for a, b in zip(row, col):
                if a == -inf or b == -inf: continue
                cur = a+b
                if cur > v: v = cur
            res[i][j] = v
    return res

def matpow(mat, e):
    n = len(mat)
    res = [[0 if i == j else -inf for j in range(n)] for i in range(n)]
    while e:
        if e & 1: res = dot(res, mat)
        mat = dot(mat, mat)
        e >>= 1
    return res

cc = LI1()
kk = LI()
n = II()

ee = [[[-inf]*16 for _ in range(16)] for _ in range(26)]
for f in range(26):
    for c in range(16):
        ee[f][c][c] = 0

for _ in range(n):
    s, a, b, e = SI().split()
    a = int1(a)
    b = int1(b)
    e = int(e)
    for f in s:
        f = ord(f)-65
        ee[f][a][b] = ee[f][b][a] = max(ee[f][a][b], e)
# p2D(ee)

ss = [0]*16
for f in range(26):
    c = cc[f]
    eef = ee[f]
    eef = matpow(eef, kk[f])
    # p2D(eef)
    for i, e in enumerate(eef[c]):
        if ss[i] == -inf: continue
        if e == -inf:
            ss[i] = -inf
        else:
            ss[i] += e
# pDB(ss)

ans = max(ss)
if ans == -inf: ans = "Impossible"
print(ans)