import sys # sys.setrecursionlimit(200005) int1 = lambda x: int(x)-1 pDB = lambda *x: print(*x, end="\n", file=sys.stderr) p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr) def II(): return int(sys.stdin.readline()) def LI(): return list(map(int, sys.stdin.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LI1(): return list(map(int1, sys.stdin.readline().split())) def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def SI(): return sys.stdin.readline().rstrip() # dij = [(0, 1), (-1, 0), (0, -1), (1, 0)] dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)] inf = (1 << 63)-1 # inf = (1 << 31)-1 # md = 10**9+7 md = 998244353 mx = 1000001 sq = set() for a in range(2, mx): sq.add(a**2) l, r = LI() r += 1 # a^2*b dp = [0]*(r-l) for a in sq: if a > r: continue s = (l+a-1)//a*a for i in range(s, r, a): dp[i-l] = 1 for a in range(1, mx): s = (l+a-1)//a*a for i in range(s, r, a): if i//a in sq: dp[i-l] = 1 print(r-l-sum(dp))