26 lines
505 B
Python
26 lines
505 B
Python
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#!/usr/bin/env python3
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def primes(n):
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sieve = [False] * n
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yield 2
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for p in range(3, n, 2):
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if sieve[p]:
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continue
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for i in range(p**2, n, 2*p):
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sieve[i] = True
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yield p
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def search(i=0, n=1, sign=1):
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r = 0
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while squares[i] * n <= N:
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m = n * squares[i]
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r += sign * (N // m)
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r += search(i+1, m, sign * (-1))
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i += 1
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return r
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N = 2**50
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squares = [p**2 for p in primes(2**25)] + [N+1]
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print(N - search())
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