MOD = 998244353

def main():
    import sys
    input = sys.stdin.read().split()
    idx = 0
    N = int(input[idx]); idx +=1
    M = int(input[idx]); idx +=1
    T = int(input[idx]); idx +=1
    
    # Initialize adjacency matrix
    A = [[0]*N for _ in range(N)]
    for _ in range(M):
        s = int(input[idx]); idx +=1
        t = int(input[idx]); idx +=1
        A[s][t] += 1
        A[t][s] += 1
    
    # Matrix multiplication function
    def multiply(a, b):
        res = [[0]*N for _ in range(N)]
        for i in range(N):
            for k in range(N):
                if a[i][k] == 0:
                    continue
                for j in range(N):
                    res[i][j] = (res[i][j] + a[i][k] * b[k][j]) % MOD
        return res
    
    # Matrix exponentiation (binary method)
    def matrix_pow(mat, power):
        # Initialize result as identity matrix
        result = [[0]*N for _ in range(N)]
        for i in range(N):
            result[i][i] = 1
        current = [row[:] for row in mat]
        while power > 0:
            if power % 2 == 1:
                result = multiply(result, current)
            current = multiply(current, current)
            power //= 2
        return result
    
    # Compute A^T
    if T == 0:
        print(1 % MOD)
        return
    A_power = matrix_pow(A, T)
    print(A_power[0][0] % MOD)

if __name__ == "__main__":
    main()