Tattah's youngest brother, Tuftuf, is new to programming.

Since his older brother is such a good programmer, his biggest dream is to outshine him. Tuftuf is a student at the German University in Cairo (GUC) where he learns to write programs in Gava.

Today, Tuftuf was introduced to Gava's unsigned integer datatypes. Gava has *n* unsigned integer datatypes of sizes (in bits) *a*<sub class="lower-index">1</sub>, *a*<sub class="lower-index">2</sub>, ... *a*<sub class="lower-index">*n*</sub>. The *i*-th datatype have size *a*<sub class="lower-index">*i*</sub> bits, so it can represent every integer between 0 and 2<sup class="upper-index">*a*<sub class="lower-index">*i*</sub></sup> - 1 inclusive. 

Tuftuf is thinking of learning a better programming language. If there exists an integer *x*, such that *x* fits in some type *i* (in *a*<sub class="lower-index">*i*</sub> bits) and *x*·*x* does not fit in some other type *j* (in *a*<sub class="lower-index">*j*</sub> bits) where *a*<sub class="lower-index">*i*</sub> &lt; *a*<sub class="lower-index">*j*</sub>, then Tuftuf will stop using Gava.

Your task is to determine Tuftuf's destiny.
The first line contains integer *n* (2 ≤ *n* ≤ 10<sup class="upper-index">5</sup>) — the number of Gava's unsigned integer datatypes' sizes. The second line contains a single-space-separated list of *n* integers (1 ≤ *a*<sub class="lower-index">*i*</sub> ≤ 10<sup class="upper-index">9</sup>) — sizes of datatypes in bits. Some datatypes may have equal sizes.
3
64 16 32
NO
4
4 2 1 3
YES
5
1 5 3 3 2
YES
52
474 24 24 954 9 234 474 114 24 114 234 24 114 114 234 9 9 24 9 54 234 54 9 954 474 9 54 54 54 234 9 114 24 54 114 954 954 474 24 54 54 234 234 474 474 24 114 9 954 954 954 474
NO
56
43 641 626 984 107 521 266 835 707 220 402 406 558 199 988 685 843 808 182 73 553 17 765 979 116 178 489 271 532 889 26 263 654 680 240 392 980 267 264 46 888 444 874 519 735 301 743 526 376 793 40 110 811 184 82 96
YES
9
20 44 92 8 20 380 8 188 764
NO
97
250 58 26 506 58 122 506 506 250 506 26 58 26 58 10 26 58 58 2 506 506 10 10 2 26 26 122 58 506 10 506 58 250 2 26 122 122 10 250 58 2 58 58 122 10 506 26 122 26 2 2 2 250 506 2 506 10 2 26 122 250 2 250 122 10 250 10 26 58 122 58 2 2 10 250 250 26 250 10 250 506 122 122 122 506 26 58 10 122 10 250 10 2 2 26 250 122
NO
85
436 23 384 417 11 227 713 910 217 177 227 161 851 396 556 948 700 819 920 451 877 249 332 189 606 986 627 468 877 682 497 579 189 443 252 795 147 642 643 569 250 863 615 560 142 752 918 167 677 49 750 871 282 721 102 884 179 980 392 509 178 977 51 241 912 599 142 975 453 353 350 130 837 955 688 7 588 239 194 277 50 865 227 848 538
YES
43
906 652 445 325 991 682 173 290 731 528 432 615 698 132 874 38 643 301 223 442 722 529 150 659 593 22 679 178 410 978 201 559 115 533 586 790 703 596 492 591 781 761 384
YES
8
421 250 398 257 512 329 25 972
YES
2
1000000000 999999999
YES
220
10 6 6 2 8 6 6 5 6 2 10 3 9 10 10 2 3 5 2 2 4 7 6 6 7 5 6 2 10 10 1 1 2 2 3 2 4 4 8 1 1 2 1 10 9 2 1 4 2 1 7 4 8 4 2 9 7 7 6 6 8 3 1 9 10 6 3 5 9 5 1 1 8 3 10 8 10 3 7 9 2 4 8 2 8 4 10 5 7 10 6 8 3 5 7 9 4 2 6 2 2 7 7 2 10 1 1 8 7 4 8 8 9 1 1 9 5 5 5 3 5 5 3 2 6 4 7 9 10 9 3 1 10 1 7 8 8 7 6 5 1 5 6 2 1 9 9 10 8 4 9 5 4 8 10 4 9 2 3 7 10 3 3 9 10 5 7 7 6 7 3 1 5 7 10 6 3 5 4 7 8 6 10 10 10 8 3 5 1 1 1 10 2 3 5 5 2 5 8 4 7 3 1 10 1 10 9 2 10 3 4 9 1 5 9 8 2 7 7 2
YES
7
1 2 3 4 8 16 32
YES
2
1 1
NO
2
1 2
NO
3
1 2 2
NO
3
1 1 2
NO
n=int(input())
a=[int(x) for x in input().split()]
a.sort()
ans="NO"
for i in range(1,n):
    if a[i]<2*a[i-1]:
        ans="YES"
        break
print(ans)
        