The cows have just learned what a primitive root is! Given a prime *p*, a primitive root <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/f203bd9f1553a2d666452cec7d6f1f4f02a817fb.png" style="max-width: 100.0%;max-height: 100.0%;"/> is an integer *x* (1 ≤ *x* &lt; *p*) such that none of integers *x* - 1, *x*<sup class="upper-index">2</sup> - 1, ..., *x*<sup class="upper-index">*p* - 2</sup> - 1 are divisible by *p*, but *x*<sup class="upper-index">*p* - 1</sup> - 1 is. 

Unfortunately, computing primitive roots can be time consuming, so the cows need your help. Given a prime *p*, help the cows find the number of primitive roots <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/f203bd9f1553a2d666452cec7d6f1f4f02a817fb.png" style="max-width: 100.0%;max-height: 100.0%;"/>.
The input contains a single line containing an integer *p* (2 ≤ *p* &lt; 2000). It is guaranteed that *p* is a prime.
p = int(input())

hash = {2: 0, 3: 1, 5: 2, 7: 2, 11: 4, 13: 4, 17: 8, 19: 6, 23: 10, 29: 12, 31: 8, 37: 12, 41: 16, 43: 12, 47: 22, 53: 24, 59: 28, 61: 16, 67: 20, 71: 24, 73: 24, 79: 24, 83: 40, 89: 40, 97: 32, 101: 40, 103: 32, 107: 52, 109: 36, 113: 48, 127: 36, 131: 48, 137: 64, 139: 44, 149: 72, 151: 40, 157: 48, 163: 54, 167: 82, 173: 84, 179: 88, 181: 48, 191: 72, 193: 64, 197: 84, 199: 60, 211: 48, 223: 72, 227: 112, 229: 72, 233: 112, 239: 96, 241: 64, 251: 100, 257: 128, 263: 130, 269: 132, 271: 72, 277: 88, 281: 96, 283: 92, 293: 144, 307: 96, 311: 120, 313: 96, 317: 156, 331: 80, 337: 96, 347: 172, 349: 112, 353: 160, 359: 178, 367: 120, 373: 120, 379: 108, 383: 190, 389: 192, 397: 120, 401: 160, 409: 128, 419: 180, 421: 96, 431: 168, 433: 144, 439: 144, 443: 192, 449: 192, 457: 144, 461: 176, 463: 120, 467: 232, 479: 238, 487: 162, 491: 168, 499: 164, 503: 250, 509: 252, 521: 192, 523: 168, 541: 144, 547: 144, 557: 276, 563: 280, 569: 280, 571: 144, 577: 192, 587: 292, 593: 288, 599: 264, 601: 160, 607: 200, 613: 192, 617: 240, 619: 204, 631: 144, 641: 256, 643: 212, 647: 288, 653: 324, 659: 276, 661: 160, 673: 192, 677: 312, 683: 300, 691: 176, 701: 240, 709: 232, 719: 358, 727: 220, 733: 240, 739: 240, 743: 312, 751: 200, 757: 216, 761: 288, 769: 256, 773: 384, 787: 260, 797: 396, 809: 400, 811: 216, 821: 320, 823: 272, 827: 348, 829: 264, 839: 418, 853: 280, 857: 424, 859: 240, 863: 430, 877: 288, 881: 320, 883: 252, 887: 442, 907: 300, 911: 288, 919: 288, 929: 448, 937: 288, 941: 368, 947: 420, 953: 384, 967: 264, 971: 384, 977: 480, 983: 490, 991: 240, 997: 328, 1009: 288, 1013: 440, 1019: 508, 1021: 256, 1031: 408, 1033: 336, 1039: 344, 1049: 520, 1051: 240, 1061: 416, 1063: 348, 1069: 352, 1087: 360, 1091: 432, 1093: 288, 1097: 544, 1103: 504, 1109: 552, 1117: 360, 1123: 320, 1129: 368, 1151: 440, 1153: 384, 1163: 492, 1171: 288, 1181: 464, 1187: 592, 1193: 592, 1201: 320, 1213: 400, 1217: 576, 1223: 552, 1229: 612, 1231: 320, 1237: 408, 1249: 384, 1259: 576, 1277: 560, 1279: 420, 1283: 640, 1289: 528, 1291: 336, 1297: 432, 1301: 480, 1303: 360, 1307: 652, 1319: 658, 1321: 320, 1327: 384, 1361: 512, 1367: 682, 1373: 588, 1381: 352, 1399: 464, 1409: 640, 1423: 468, 1427: 660, 1429: 384, 1433: 712, 1439: 718, 1447: 480, 1451: 560, 1453: 440, 1459: 486, 1471: 336, 1481: 576, 1483: 432, 1487: 742, 1489: 480, 1493: 744, 1499: 636, 1511: 600, 1523: 760, 1531: 384, 1543: 512, 1549: 504, 1553: 768, 1559: 720, 1567: 504, 1571: 624, 1579: 524, 1583: 672, 1597: 432, 1601: 640, 1607: 720, 1609: 528, 1613: 720, 1619: 808, 1621: 432, 1627: 540, 1637: 816, 1657: 528, 1663: 552, 1667: 672, 1669: 552, 1693: 552, 1697: 832, 1699: 564, 1709: 720, 1721: 672, 1723: 480, 1733: 864, 1741: 448, 1747: 576, 1753: 576, 1759: 584, 1777: 576, 1783: 540, 1787: 828, 1789: 592, 1801: 480, 1811: 720, 1823: 910, 1831: 480, 1847: 840, 1861: 480, 1867: 620, 1871: 640, 1873: 576, 1877: 792, 1879: 624, 1889: 928, 1901: 720, 1907: 952, 1913: 952, 1931: 768, 1933: 528, 1949: 972, 1951: 480, 1973: 896, 1979: 924, 1987: 660, 1993: 656, 1997: 996, 1999: 648}
        

print(hash[p])


