Peter got a new snow blower as a New Year present. Of course, Peter decided to try it immediately. After reading the instructions he realized that it does not work like regular snow blowing machines. In order to make it work, you need to tie it to some point that it does not cover, and then switch it on. As a result it will go along a circle around this point and will remove all the snow from its path.

Formally, we assume that Peter's machine is a polygon on a plane. Then, after the machine is switched on, it will make a circle around the point to which Peter tied it (this point lies strictly outside the polygon). That is, each of the points lying within or on the border of the polygon will move along the circular trajectory, with the center of the circle at the point to which Peter tied his machine.

Peter decided to tie his car to point *P* and now he is wondering what is the area of ​​the region that will be cleared from snow. Help him.
The first line of the input contains three integers — the number of vertices of the polygon *n* (<img align="middle" class="tex-formula" src="https://espresso.codeforces.com/5b059d10e00a903bb105cfb827a89ceb19833f07.png" style="max-width: 100.0%;max-height: 100.0%;"/>), and coordinates of point *P*.

Each of the next *n* lines contains two integers — coordinates of the vertices of the polygon in the clockwise or counterclockwise order. It is guaranteed that no three consecutive vertices lie on a common straight line.

All the numbers in the input are integers that do not exceed 1 000 000 in their absolute value.
In the first sample snow will be removed from that area:
3 0 0
0 1
-1 2
1 2
12.566370614359172464
4 1 -1
0 0
1 2
2 0
1 1
21.991148575128551812
3 0 0
-1 1
0 3
1 1
25.132741228718344928
3 -4 2
-3 2
5 -5
5 3
405.26545231308331191
3 -84 8
-83 8
21 -62
3 53
50026.721415763865583
6 -94 -51
-93 -51
48 -25
61 27
73 76
-10 87
-48 38
138283.48383306192359
5 -94 52
-93 52
-78 -56
-54 -81
56 -87
97 85
131381.40477312514811
10 -100 90
-99 90
-98 -12
-72 -87
7 -84
86 -79
96 -2
100 36
99 59
27 83
-14 93
198410.42563011697403
11 -97 -15
-96 -15
-83 -84
-61 -97
64 -92
81 -82
100 -63
86 80
58 95
15 99
-48 83
-91 49
133558.52848206287476
10 -500 420
-499 420
-489 -173
-455 -480
160 -464
374 -437
452 -352
481 -281
465 75
326 392
-398 468
4719573.802783449531
10 -498 -161
-497 -161
-427 -458
-325 -475
349 -500
441 -220
473 28
475 62
468 498
-444 492
-465 264
4295926.8918542123392
5 -1 -1
0 0
8 5
10 7
7 5
2 5
574.91145560693214023
5 -1 -1
0 0
20 3
26 17
23 21
98 96
60343.711690152746165
10 -1 -1
0 0
94 7
100 52
87 48
37 26
74 61
59 57
87 90
52 90
26 73
50337.739088469255101
10 -1 -1
0 0
78 22
53 24
78 50
46 39
45 56
21 46
2 7
24 97
5 59
32129.068068262814194
49 -1 -1
0 0
95 2
47 1
42 1
93 7
56 6
47 7
63 13
98 24
94 27
90 28
86 28
17 6
64 24
42 19
66 35
63 35
98 60
75 48
28 18
71 46
69 46
99 68
64 47
56 43
72 58
35 29
82 81
68 69
79 84
72 77
79 86
54 59
35 39
20 23
73 86
80 97
79 100
69 99
29 45
26 63
23 56
12 33
13 39
25 85
27 96
6 23
4 47
1 60
52147.296456936975932
49 -1 -1
0 0
69 2
74 7
62 10
64 15
93 22
78 22
56 17
86 29
24 9
91 43
8 4
90 50
99 57
39 23
81 50
91 58
67 46
95 66
52 39
91 69
69 54
93 84
93 98
70 80
85 98
30 39
55 79
41 59
50 72
57 88
58 92
58 94
37 63
43 87
30 63
19 40
38 81
40 86
38 100
2 6
30 100
23 89
16 62
11 49
12 64
9 52
5 62
1 88
58543.579099645794717
27 -999899 136015
-999898 136015
-999877 -297518
-999832 -906080
-999320 -977222
-998896 -995106
-962959 -999497
-747200 -999814
417261 -999929
844204 -999911
959527 -999826
998944 -999180
999413 -989979
999556 -943026
999871 -774660
999993 -261535
999963 938964
998309 991397
989894 997814
988982 998459
987145 999235
972224 999741
603140 999994
-812452 999962
-980920 999788
-996671 987674
-999472 977919
-999808 639816
16600304470662.964855
19 -995486 -247212
-995485 -247212
-995004 -492984
-993898 -887860
-938506 -961227
-688481 -971489
178005 -999731
541526 -999819
799710 -988908
905862 -967693
987335 -887414
983567 824667
973128 892799
914017 960546
669333 986330
-441349 986800
-813005 986924
-980671 973524
-988356 849906
-995289 404864
16257949833603.158278
15 -994057 554462
-994056 554462
-975707 -994167
-711551 -996810
13909 -997149
809315 -993832
980809 -984682
996788 -303578
993267 173570
978439 877361
898589 957311
725925 992298
-57849 999563
-335564 997722
-989580 990530
-993875 973633
19694832748836.689348
23 -999840 738880
-999839 738880
-998291 -847192
-995443 -982237
-906770 -996569
360950 -999295
800714 -998808
985348 -995579
990091 -928438
996690 -817256
998844 -736918
998377 674949
998008 862436
993320 971157
978831 979400
853341 986660
802107 989497
513719 996183
140983 998592
-158810 999459
-677966 999174
-949021 981608
-982951 976421
-993452 962292
21831930831113.094931
20 -999719 -377746
-999718 -377746
-997432 -940486
-982215 -950088
-903861 -997725
-127953 -999833
846620 -999745
920305 -992903
947027 -986746
991646 -959876
998264 -944885
999301 870671
994737 985066
640032 998502
-87871 999984
-450900 999751
-910919 999086
-971174 995672
-995406 975642
-998685 946525
-999684 673031
18331542740428.216614
26 -999922 -339832
-999921 -339832
-999666 -565163
-998004 -942175
-992140 -985584
-965753 -998838
-961074 -999911
120315 -999489
308422 -999258
696427 -997199
724780 -996955
995651 -985203
997267 -975745
999745 -941705
999897 -770648
999841 -211766
999436 865172
999016 992181
980442 997414
799072 998987
348022 999183
-178144 999329
-729638 998617
-953068 997984
-991172 990824
-997976 939889
-999483 581509
18127026556380.411608
22 -999930 -362070
-999929 -362070
-994861 -919993
-989365 -946982
-964007 -997050
-418950 -998064
351746 -998882
830925 -996765
867755 -996352
964401 -992258
996299 -964402
997257 -930788
999795 -616866
999689 327482
997898 996234
923521 997809
631104 998389
-261788 999672
-609744 999782
-694662 999001
-941227 993687
-997105 992436
-999550 895326
18335297542813.80731
29 -999961 689169
-999960 689169
-999927 -938525
-999735 -989464
-993714 -997911
-870186 -999686
-796253 -999950
-139940 -999968
969552 -999972
985446 -999398
992690 -997295
999706 -973137
999898 -848630
999997 -192297
999969 773408
999495 960350
999143 981671
998324 993987
997640 998103
986157 998977
966840 999418
670113 999809
477888 999856
129160 999900
-373564 999947
-797543 999976
-860769 999903
-995496 999355
-998771 984570
-999768 927157
21409384775316.574772
3 -3 3
-3 2
5 -5
5 3
399.0305992005743379
3 -9 7
-9 6
3 -6
4 2
980.17690792001545219
5 -9 8
-9 7
-6 -1
-3 -6
1 -3
10 8
1130.9820337250702449
6 -6 -1
-6 -2
0 -7
8 -9
9 -1
5 10
-5 0
816.18577140262825159
10 -99 91
-99 90
-98 -12
-72 -87
7 -84
86 -79
96 -2
100 36
99 59
27 83
-14 93
198309.89857373595223
11 -96 -14
-96 -15
-83 -84
-61 -97
64 -92
81 -82
100 -63
86 80
58 95
15 99
-48 83
-91 49
131821.20868619133483
13 -98 25
-98 24
-96 10
-80 -71
-71 -78
-31 -99
82 -98
92 -39
94 -2
94 40
90 80
50 96
-41 97
-86 80
149316.61930888936332
17 -99 -53
-99 -54
-97 -71
-67 -99
-61 -99
56 -98
82 -85
95 -47
90 -2
82 30
63 87
54 95
-12 99
-38 99
-87 89
-90 87
-95 67
-96 49
144023.17094830233827
19 -995485 -247211
-995485 -247212
-995004 -492984
-993898 -887860
-938506 -961227
-688481 -971489
178005 -999731
541526 -999819
799710 -988908
905862 -967693
987335 -887414
983567 824667
973128 892799
914017 960546
669333 986330
-441349 986800
-813005 986924
-980671 973524
-988356 849906
-995289 404864
16257930301545.657524
15 -994056 554463
-994056 554462
-975707 -994167
-711551 -996810
13909 -997149
809315 -993832
980809 -984682
996788 -303578
993267 173570
978439 877361
898589 957311
725925 992298
-57849 999563
-335564 997722
-989580 990530
-993875 973633
19694830011124.045712
23 -999839 738881
-999839 738880
-998291 -847192
-995443 -982237
-906770 -996569
360950 -999295
800714 -998808
985348 -995579
990091 -928438
996690 -817256
998844 -736918
998377 674949
998008 862436
993320 971157
978831 979400
853341 986660
802107 989497
513719 996183
140983 998592
-158810 999459
-677966 999174
-949021 981608
-982951 976421
-993452 962292
21831929255745.74826
20 -999718 -377745
-999718 -377746
-997432 -940486
-982215 -950088
-903861 -997725
-127953 -999833
846620 -999745
920305 -992903
947027 -986746
991646 -959876
998264 -944885
999301 870671
994737 985066
640032 998502
-87871 999984
-450900 999751
-910919 999086
-971174 995672
-995406 975642
-998685 946525
-999684 673031
18331521646100.671528
26 -999921 -339831
-999921 -339832
-999666 -565163
-998004 -942175
-992140 -985584
-965753 -998838
-961074 -999911
120315 -999489
308422 -999258
696427 -997199
724780 -996955
995651 -985203
997267 -975745
999745 -941705
999897 -770648
999841 -211766
999436 865172
999016 992181
980442 997414
799072 998987
348022 999183
-178144 999329
-729638 998617
-953068 997984
-991172 990824
-997976 939889
-999483 581509
18127005627407.454252
22 -999929 -362069
-999929 -362070
-994861 -919993
-989365 -946982
-964007 -997050
-418950 -998064
351746 -998882
830925 -996765
867755 -996352
964401 -992258
996299 -964402
997257 -930788
999795 -616866
999689 327482
997898 996234
923521 997809
631104 998389
-261788 999672
-609744 999782
-694662 999001
-941227 993687
-997105 992436
-999550 895326
18335276455623.960732
27 -999898 136016
-999898 136015
-999877 -297518
-999832 -906080
-999320 -977222
-998896 -995106
-962959 -999497
-747200 -999814
417261 -999929
844204 -999911
959527 -999826
998944 -999180
999413 -989979
999556 -943026
999871 -774660
999993 -261535
999963 938964
998309 991397
989894 997814
988982 998459
987145 999235
972224 999741
603140 999994
-812452 999962
-980920 999788
-996671 987674
-999472 977919
-999808 639816
16600299044211.965457
13 -1000000 -1000000
-1000000 0
0 -1000000
999417 840
999781 33421
999994 131490
999993 998865
962080 999911
629402 999973
378696 999988
53978 999788
25311 999558
6082 999282
1565 998489
23547598153913.984406
16 -1000000 -1000000
-1000000 0
0 -1000000
999744 572
999931 96510
1000000 254372
999939 748173
999894 953785
999683 986098
999051 999815
980586 999969
637250 999988
118331 999983
27254 999966
9197 999405
4810 997733
1661 995339
23547697574489.259052
4 0 0
1 -1
1 3
3 3
3 -1
53.407075111026482965
3 0 0
-10 1
0 2
1 1
314.1592653589793116
3 0 0
-1 1
4 1
0 2
50.265482457436689849
import math

PI = 3.141592653589793
r_max = 0
r_min = 2*(10**12)

def dot(v1, v2):
    return v1[0]*v2[0] + v1[1]*v2[1]

def cross(v1, v2):
    return v1[0]*v2[1] - v1[1]*v2[0]

def mag(x,y):
    return math.sqrt(x**2 + y**2)

def main():
    n, x0, y0 = map(int, input().split())

    x, y = x0, y0
    for _ in range(n):
        x_, y_ = map(int, input().split())
        x_, y_ = x_ - x0, y_ - y0
        if x == x0 and y == y0:
            x, y = x_, y_
            
        r_max = max(mag(x_, y_), r_max)
        r_min = min(mag(x_, y_), r_min)

        if dot([x,y],[x-x_, y-y_])*dot([x_,y_],[x-x_,y-y_]) > 0:
            c = cross([x,y],[x-x_,y-y_])
            r_min = min(c / mag(x-x_,y-y_), r_min)
    
        x, y = x_, y_

    print((r_max**2 - r_min**2) * PI)

if __name__ == '__main__':
    main()