// yukicoder: No.368 LCM of K-products // 2019.4.15 bal4u #include #include #include #include //// 高速入力 #if 1 #define gc() getchar_unlocked() #else #define gc() getchar() #endif int in() // 非負整数の入力 { int n = 0, c = gc(); do n = 10 * n + (c & 0xf), c = gc(); while (c >= '0'); return n; } //// 本問題関連グローバルデータ #define MOD 1000000007 int hi[10000], *tbl[10000], fa[10000]; int sz; //// ハッシュテーブル(値からIDを得る) #define HASHSIZ 99991 typedef struct { int n, id; } HASH; HASH hash[HASHSIZ+5], *hashend = hash + HASHSIZ; int lookup(int n) { HASH *p = hash + n % HASHSIZ; while (p->n) { if (p->n == n) return p->id; if (++p == hashend) p = hash; } return -1; } int insert(int n, int id) { HASH *p = hash + n % HASHSIZ; while (p->n) { if (p->n == n) return p->id; if (++p == hashend) p = hash; } p->n = n, p->id = id; return -1; } //// 素因数分解モジュール #define MAX 1005 #define SIZE 25 // 先頭の10個素因数の積 2x3x5..x29 = 6.4x10^9 int factor[MAX][SIZE], power[MAX][SIZE], len[MAX]; int ptbl[] = { 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997, 0 }; void prime_factor(int id, int n) { int i, k, d, size; int *pp; size = 0; if ((n & 1) == 0) { factor[id][size] = 2; if ((k = insert(2, sz)) < 0) { k = sz++, fa[k] = 2; } hi[k]++; do n >>= 1, power[id][size]++; while ((n & 1) == 0); size++; } for (pp = ptbl; n > 1 && *pp > 0; pp++) { if (n % *pp) continue; d = *pp; factor[id][size] = d; if ((k = insert(d, sz)) < 0) { k = sz++, fa[k] = d; } hi[k]++; do n /= d, power[id][size]++; while (n % d == 0); size++; } if (n > 1) { int b = (int)sqrt(n); for (i = 1009; n > 1; i += 2) { if (i > b) { factor[id][size] = n, power[id][size++] = 1; if ((k = insert(n, sz)) < 0) { k = sz++; fa[k] = n; } hi[k]++; break; } if (n % i == 0) { factor[id][size] = i; if ((k = insert(i, sz)) < 0) { k = sz++; fa[k] = i; } hi[k]++; do n /= i, power[id][size]++; while (n % i == 0); size++; } } } len[id] = size; } //// powの高速計算 int bigPow(int x, int p) { int r = 1; while (p) { if (p & 1) r = (long long)r * x % MOD; x = (long long)x * x % MOD; p >>= 1; } return r; } //// 本問題関連 int cmp(const void *a, const void *b) { return *(int *)b - *(int *)a; } int main() { int i, j, k, p, N, K; long long ans; N = in(), K = in(); for (i = 0; i < N; i++) prime_factor(i, in()); for (i = 0; i < sz; i++) tbl[i] = malloc(hi[i] * sizeof(int)); memset(hi, 0, sizeof(int)*sz); for (i = 0; i < N; i++) { for (j = 0; j < len[i]; j++) { k = lookup(factor[i][j]); tbl[k][hi[k]++] = power[i][j]; } } ans = 1; for (i = 0; i < sz; i++) { if (hi[i] > K) qsort(tbl[i], hi[i], sizeof(int), cmp); p = 0; for (j = 0; j < K && j < hi[i]; j++) p += tbl[i][j]; ans = (ans * bigPow(fa[i], p)) % MOD; } printf("%d\n", (int)ans); return 0; }