def cal(a,b,n):
  res = [[0 for i in range(n)] for i in range(n)]
  for i in range(n):
    for j in range(n):
      for k in range(n):
        res[i][j] += a[i][k]*b[k][j]
        res[i][j] %= mod
  return res

n,m,T = map(int,input().split())
l = [[0 for i in range(n)] for i in range(n)]
mod = 998244353
for i in range(m):
  s,t = map(int,input().split())
  l[s][t] = 1
  l[t][s] = 1
matrix = [l]
for i in range(60):
  matrix.append(cal(matrix[-1],matrix[-1],n))
now = [[0 for i in range(n)] for i in range(n)]
for i in range(n):
  now[i][i] = 1
s = format(T,'061b')[::-1]
for i in range(61):
  if s[i] == '1':
    now = cal(now,matrix[i],n)
print(now[0][0])