import math dic = {} rec = [] def iszhishu(x): if x==2: return True for i in range(2,int(math.sqrt(x))+1): if x%i==0: return False return True for i in range(2,n+1): if iszhishu(i): dic[i]=1 rec.append(i) else: for j in rec: if i%j==0: dic[i]=dic[i//j]+1 ans = 0 for i in range(2,n+1): ans += dic[i] print(ans)