Go: package main

import "fmt"

func main() {
	var i int64
	var list = []int64{13, 19, 109, 199, 829, 1489, 1879, 2089, 3259, 3469, 5659, 9439, 13009, 15649, 15739, 16069, 18049, 18919, 19429, 21019, 22279, 25309, 31729, 34849, 43789, 51349, 55339, 62989, 67219, 69499, 72229, 77269, 79699, 81049, 82729, 88819, 97849, 99139, 101119, 109849, 116539, 119299, 122209, 135469, 144169, 157279, 165709, 166849, 171169, 187639, 194869, 195739, 201499, 201829, 217369, 225349, 240049, 243709, 247609, 247999, 257869, 260419, 266689, 268819, 276049, 284749, 285289, 294319, 295879, 299479, 300499, 301999, 326149, 334429, 340939, 346399, 347989, 354259, 358909, 361219, 375259, 388699, 389569, 392269, 394819, 397549, 397759, 402139, 402769, 412039, 419059, 420859, 427249, 442579, 444349, 452539, 463459, 465169, 467479, 470089, 477019, 490579, 495619, 500239, 510619, 518809, 536449, 536779, 539509, 549169, 559219, 563419, 570049, 572659, 585919, 594829, 597679, 607309, 622249, 626629, 632089, 632329, 633469, 633799, 654169, 657499, 661099, 663589, 664669, 666439, 680299, 681259, 691729, 705169, 715159, 734479, 736369, 739399, 768199, 773029, 795799, 803449, 814069, 822169, 823729, 829729, 833719, 837079, 845989, 854929, 855739, 857959, 875269, 876019, 881479, 889879, 907399, 930079, 938059, 946669, 954979, 958549, 959479, 976309, 978079, 983449, 1002349, 1003369, 1006309, 1006339, 1008859, 1015369, 1022389, 1022509, 1023949, 1027759, 1043599, 1063969, 1065019, 1068259, 1068709, 1091269, 1093069, 1093999, 1100839, 1117609, 1117819, 1118869, 1120549, 1121839, 1122139, 1126669, 1137889, 1146799, 1155619, 1156039, 1157839, 1163719, 1167709, 1168249, 1170139, 1172029, 1172539, 1173589, 1182289, 1210879, 1228399, 1230379, 1233439, 1246249, 1246369, 1257079, 1272289, 1285519, 1298119, 1322179, 1322599, 1324579, 1329709, 1337269, 1339909, 1340329, 1351249, 1352209, 1358809, 1360789, 1368469, 1381279, 1400809, 1402369, 1410979, 1440589, 1447009, 1451839, 1461409, 1468639, 1508629, 1514329, 1524079, 1525969, 1540969, 1571749, 1573549, 1573939, 1577299, 1584439, 1588759, 1592869, 1603339, 1615849, 1616809, 1621729, 1627609, 1631059, 1653109, 1659109, 1670569, 1678759, 1681879, 1685449, 1691869, 1711819, 1718869, 1727779, 1747729, 1748479, 1749499, 1755829, 1764229, 1780489, 1791739, 1797379, 1798639, 1802659, 1819849, 1830349, 1833529, 1834039, 1837399, 1857679, 1890529, 1902619, 1904479, 1910269, 1912069, 1912459, 1915939, 1917739, 1925389, 1943659, 1954159, 1954369, 1959319, 1979149, 1979899, 2002339, 2007619, 2007919, 2016409, 2020729, 2050339, 2062009, 2063779, 2065579, 2075839, 2079199, 2083519, 2084449, 2087389, 2107669, 2116579, 2136139, 2141809, 2143489, 2144509, 2157739, 2159239, 2168659, 2176639, 2177509, 2193889, 2202799, 2203969, 2223679, 2225059, 2246149, 2248249, 2256349, 2262979, 2266639, 2289649, 2290039, 2294059, 2303599, 2340259, 2342779, 2362279, 2373409, 2376169, 2381089, 2403889, 2413429, 2418679, 2423419, 2443789, 2458669, 2470339, 2478529, 2479669, 2499949, 2508049, 2535109, 2541949, 2546239, 2552119, 2552659, 2561269, 2564329, 2576599, 2594959, 2594989, 2596669, 2604739, 2614069, 2635489, 2668249, 2673529, 2674549, 2679499, 2683789, 2696929, 2704909, 2712379, 2715289, 2728549, 2731699, 2731909, 2759299, 2761729, 2764129, 2790259, 2805169, 2822719, 2839939, 2840269, 2846869, 2849689, 2875339, 2879299, 2893489, 2918569, 2927599, 2927809, 2952799, 2954689, 2989039, 2990839, 3047419, 3058879, 3062209, 3063499, 3066829, 3076399, 3089329, 3092569, 3101479, 3103279, 3129619, 3153589, 3157579, 3171739, 3187609, 3200209, 3207439, 3208819, 3215749, 3224869, 3243349, 3277699, 3295549, 3308959, 3326629, 3328909, 3340879, 3366829, 3371449, 3374479, 3378049, 3400219, 3416059, 3436249, 3437719, 3467539, 3479899, 3512059, 3512239, 3512989, 3513079, 3514549, 3518329, 3550699, 3584929, 3586909, 3593509, 3621469, 3652939, 3669769, 3690529, 3713449, 3727729, 3735169, 3741169, 3798079, 3817819, 3837139, 3837859, 3849829, 3854119, 3894049, 3919219, 3919

Python: # AOJ 0222 Prime Quadruplet
# Python3 2018.6.23 bal4u
# From Wekipedia (https://en.wikipedia.org/wiki/Prime_quadruplet)
# All prime quadruplets except {5, 7, 11, 13} are of the form
# {30n + 11, 30n + 13, 30n + 17, 30n + 19} for some integer n.

MAX = 899
diff = (0,3,3,21,22,13,7,39,7,73, \
126,119,88,3,11,66,29,17,53,42, \
101,214,104,298,252,133,255,141,76,91, \
168,81,45,56,203,301,43,66,291,223, \
92,97,442,290,437,281,38,144,549,241, \
29,192,11,518,266,490,122,130,13,329, \
85,209,71,241,290,18,301,52,120,34, \
50,805,276,217,182,53,209,155,77,468, \
448,29,90,85,91,7,146,21,309,234, \
60,213,511,59,273,364,57,77,87,231, \
452,168,154,346,273,588,11,91,322,335, \
140,221,87,442,297,95,321,498,146,182, \
8,38,11,679,111,120,83,36,59,462, \
32,349,448,333,644,63,101,960,161,759, \
255,354,270,52,200,133,112,297,298,27, \
74,577,25,182,280,584,756,266,287,277, \
119,31,561,59,179,630,34,98,1,84, \
217,234,4,48,127,528,679,35,108,15, \
752,60,31,228,559,7,35,56,43,10, \
151,374,297,294,14,60,196,133,18,63, \
63,17,35,290,953,584,66,102,427,4, \
357,507,441,420,802,14,66,171,252,88, \
14,364,32,220,66,256,427,651,52,287, \
987,214,161,319,241,1333,190,325,63,500, \
1026,60,13,112,238,144,137,349,417,32, \
164,196,115,735,200,382,273,104,119,214, \
665,235,297,665,25,34,211,280,542,375, \
188,42,134,573,350,106,17,112,676,1095, \
403,62,193,60,13,116,60,255,609,350, \
7,165,661,25,748,176,10,283,144,987, \
389,59,60,342,112,144,31,98,676,297, \
652,189,56,34,441,50,314,266,29,546, \
297,39,657,46,703,70,270,221,122,767, \
13,134,318,1222,84,650,371,92,164,760, \
318,175,158,679,496,389,273,38,676,270, \
902,228,143,196,18,287,102,409,612,1, \
56,269,311,714,1092,176,34,165,143,438, \
266,249,97,442,105,7,913,81,80,871, \
497,585,574,11,220,94,855,132,473,836, \
301,7,833,63,1145,60,1886,382,111,43, \
111,319,431,108,297,60,878,799,133,472, \
529,420,241,46,231,304,616,1145,595,447, \
589,76,399,865,154,101,119,739,528,673, \
49,994,412,1072,6,25,3,49,126,1079, \
1141,66,220,932,1049,561,692,764,476,248, \
200,1897,658,644,24,399,143,1331,839,1, \
1077,760,11,34,658,36,647,21,528,242, \
98,529,24,1117,192,396,930,224,365,66, \
557,377,757,322,203,335,770,155,97,21, \
665,484,553,321,207,116,574,272,287,253, \
637,259,38,263,62,1268,451,693,756,630, \
357,105,32,581,455,153,540,350,91,210, \
409,270,377,442,490,615,424,52,890,199, \
102,1746,462,749,24,644,540,220,840,1656, \
223,74,434,179,665,923,428,307,875,50, \
2387,276,109,363,529,550,139,798,176,150, \
297,123,66,266,414,17,130,1344,300,1799, \
8,1176,279,351,461,396,112,626,498,931, \
2782,123,1253,780,781,1119,46,39,847,468, \
1037,1144,63,332,294,1082,525,459,220,70, \
231,31,1029,256,290,662,242,98,252,13, \
1008,64,346,1211,119,802,189,272,298,122, \
697,319,195,273,410,1221,365,885,322,52, \
847,165,112,67,812,630,801,87,60,424, \
630,867,231,123,308,396,76,119,60,203, \
17,63,553,931,147,588,127,437,164,43, \
14,371,115,150,354,315,473,3,1221,245, \
36,272,214,24,385,249,182,445,171,35, \
921,300,1558,1250,129,539,476,94,11,227, \
427,151,102,126,2176,71,297,60,413,195, \
190,944,49,554,1102,676,279,78,143,364, \
357,462,1144,1050,218,423,623,364,416,239, \
143,280,248,365,77,77,1529,157,361,514, \
536,31,330,87,193,514,935,227,18,91, \
104,49,133,1149,104,518,396,1015,143,445, \
360,385,680,49,1053,669,647,931,140,231, \
31,1075,483,627,101,1012,714,346,504,60, \
917,1140,1180,98,297,1029,225,1918,406,188, \
368,466,1305,1117,1028,50,150,273,333,101, \
151,146,1100,119,1532,497,487,235,658,322, \
538,210,701,574,136,220,168,105,603,332, \
409,84,81,39,860,309,384,259,266,207, \
872,377,403,248,819,882,931,148,42,371, \
805,325,668,529,409,3151,2016,14,38,1487, \
350,295,266,343,1833,1887,123,370,260,696, \
137,962,410,132,847,1051,426,39,214,546, \
539,493,325,137,112,889,130,237,43,1183, \
118,371,1,580,316,434,2698,53,98,262, \
203,119,31,189,813,119,195,294,1435,1345, \
531,624,210,231,321,553,11,756,1358)

import bisect

tbl = [0]*MAX
for i in range(1, MAX): tbl[i] = tbl[i-1] + diff[i]
for i in range(MAX): tbl[i] = tbl[i]*30+19
while 1:
	n = int(input())
	if n == 0: break
	if n < 19: print("13")
	else:
		p = bisect.bisect_left(tbl, n)
		if tbl[p] == n: print(n)
		else: print(tbl[p-1])