class comb():

  F = [1, 1]

  Fi = [1, 1]

  I = [0, 1]

  def __init__(self, num, mod):

    self.MOD = mod

    for i in range(2, num + 1):

      self.F.append((self.F[-1] * i) % mod)

      self.I.append(mod - self.I[mod % i] * (mod // i) % mod)

      self.Fi.append(self.Fi[-1] * self.I[i] % mod)

  def com(self, n, k):

    if n < k: return 0

    if n < 0 or k < 0: return 0

    return self.F[n] * (self.Fi[k] * self.Fi[n - k] % self.MOD) % self.MOD





K = int(eval(input()))

S = eval(input())

MOD = 10 ** 9 + 7



N = K + len(S)

M = len(S)

com = comb(N + 1, MOD)



p25 = [1]

p26 = [1]

for i in range(K + 1):

  p25.append(p25[-1] * 25 % MOD)

  p26.append(p26[-1] * 26 % MOD)



ans = 0



for i in range(K + 1):

  ans = (ans + p25[i] * com.com(M + i  - 1, M - 1) * p26[K - i]) % MOD



print(ans)

class comb():

  F = [1, 1]

  Fi = [1, 1]

  I = [0, 1]

  def __init__(self, num, mod):

    self.MOD = mod

    for i in range(2, num + 1):

      self.F.append((self.F[-1] * i) % mod)

      self.I.append(mod - self.I[mod % i] * (mod // i) % mod)

      self.Fi.append(self.Fi[-1] * self.I[i] % mod)

  def com(self, n, k):

    if n < k: return 0

    if n < 0 or k < 0: return 0

    return self.F[n] * (self.Fi[k] * self.Fi[n - k] % self.MOD) % self.MOD





K = int(eval(input()))

S = eval(input())

MOD = 10 ** 9 + 7



N = K + len(S)

M = len(S)

com = comb(N + 1, MOD)



p25 = [1]

for i in range(N + 1):

  p25.append(p25[-1] * 25 % MOD)



ans = 0



for i in range(K + 1):

  t = M + i

  ans = (ans + p25[N - t] * com.com(N, t)) % MOD



print(ans)

class comb:
    F = [1, 1]
    Fi = [1, 1]
    I = [0, 1]

    def __init__(self, num, mod):
        self.MOD = mod
        for i in range(2, num + 1):
            self.F.append((self.F[-1] * i) % mod)
            self.I.append(mod - self.I[mod % i] * (mod // i) % mod)
            self.Fi.append(self.Fi[-1] * self.I[i] % mod)

    def com(self, n, k):
        if n < k:
            return 0
        if n < 0 or k < 0:
            return 0
        return self.F[n] * (self.Fi[k] * self.Fi[n - k] % self.MOD) % self.MOD


K = int(eval(input()))
S = eval(input())
MOD = 10**9 + 7
N = K + len(S)
M = len(S)
com = comb(N + 1, MOD)
p25 = [1]
p26 = [1]
for i in range(K + 1):
    p25.append(p25[-1] * 25 % MOD)
    p26.append(p26[-1] * 26 % MOD)
ans = 0
for i in range(K + 1):
    ans = (ans + p25[i] * com.com(M + i - 1, M - 1) * p26[K - i]) % MOD
print(ans)

class comb:
    F = [1, 1]
    Fi = [1, 1]
    I = [0, 1]

    def __init__(self, num, mod):
        self.MOD = mod
        for i in range(2, num + 1):
            self.F.append((self.F[-1] * i) % mod)
            self.I.append(mod - self.I[mod % i] * (mod // i) % mod)
            self.Fi.append(self.Fi[-1] * self.I[i] % mod)

    def com(self, n, k):
        if n < k:
            return 0
        if n < 0 or k < 0:
            return 0
        return self.F[n] * (self.Fi[k] * self.Fi[n - k] % self.MOD) % self.MOD


K = int(eval(input()))
S = eval(input())
MOD = 10**9 + 7
N = K + len(S)
M = len(S)
com = comb(N + 1, MOD)
p25 = [1]
for i in range(N + 1):
    p25.append(p25[-1] * 25 % MOD)
ans = 0
for i in range(K + 1):
    t = M + i
    ans = (ans + p25[N - t] * com.com(N, t)) % MOD
print(ans)

-p26 = [1] -for i in range(K + 1): +for i in range(N + 1): -    p26.append(p26[-1] * 26 % MOD) -    ans = (ans + p25[i] * com.com(M + i - 1, M - 1) * p26[K - i]) % MOD +    t = M + i +    ans = (ans + p25[N - t] * com.com(N, t)) % MOD