import sys def main(): it = iter(sys.stdin.buffer.read().split()) try: N = int(next(it)) except StopIteration: return X = int(next(it)) Q = int(next(it)) ans = 0.0 for _ in range(Q): m = int(next(it)) seen = set() repeated = False x_present = False for _ in range(m): a = int(next(it)) if a == X: x_present = True if a in seen: repeated = True else: seen.add(a) if x_present: ans += 1.0 elif repeated: ans += 0.5 # else add 0.0 # Print with enough precision print("{:.10f}".format(ans).rstrip('0').rstrip('.') if abs(ans - round(ans)) > 1e-12 else str(int(round(ans)))) if __name__ == "__main__": main()