MOD = 998244353

def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    idx = 0
    N = int(data[idx]); idx +=1
    M = int(data[idx]); idx +=1
    T = int(data[idx]); idx +=1
    
    # Initialize adjacency matrix
    adj = [[0]*N for _ in range(N)]
    for _ in range(M):
        s = int(data[idx]); idx +=1
        t = int(data[idx]); idx +=1
        adj[s][t] += 1
        adj[t][s] += 1
    
    # Function to multiply two matrices with optimization
    def multiply(a, b):
        n = len(a)
        result = [[0]*n for _ in range(n)]
        bt = list(zip(*b))  # Transpose b
        for i in range(n):
            a_row = a[i]
            for j in range(n):
                total = 0
                b_col = bt[j]
                for k in range(n):
                    total += a_row[k] * b_col[k]
                result[i][j] = total % MOD
        return result
    
    # Function to compute matrix exponentiation using binary exponentiation
    def matrix_power(mat, power):
        n = len(mat)
        result = [[0]*n for _ in range(n)]
        for i in range(n):
            result[i][i] = 1  # Identity matrix
        current = mat
        while power > 0:
            if power % 2 == 1:
                result = multiply(result, current)
            current = multiply(current, current)
            power = power // 2
        return result
    
    if T == 0:
        print(1 % MOD)
        return
    
    # Compute A^T
    mat_T = matrix_power(adj, T)
    
    # The result is the (0,0) entry of mat_T
    print(mat_T[0][0] % MOD)

if __name__ == "__main__":
    main()