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02/10/2023 16:43:16

# Рабочее место участника

## Задачи

1929. Strength

Ограничения: время – 1s/2s, память – 64MiB Ввод: input.txt или стандартный ввод Вывод: output.txt или стандартный вывод Послать решение Blockly Посылки Темы Где Обсудить (0)

Let us begin with a positive integer N and find the smallest positive integer which doesn't divide N. If we repeat the procedure with the resulting number, then again with the new result and so on, we will eventually obtain the number 2 (two). Let us define "strength"(N) as the length of the resulting sequence.
For example, for N\ =\ 6 we obtain the sequence 6,\ 4,\ 3,\ 2 which consists of 4 numbers, thus "strength"(6)\ =\ 4.
Given two positive integers A\ \ <\ \ B, calculate the sum of strengths of all integers between A and B (inclusive), that is,
"strength"(A)\ +\ "strength"(A\ +\ 1)\ +\ …\ +\ "strength"(B).
The first and only line of input contains two positive integers, A and B (3\ ≤\ A\ <\ B\ <\ 10^17).
The first and only line of output should contain the requested sum of strengths.

Sample Input #1

3 6


Sample Output #1

11


Sample Input #2

100 200


Sample Output #2

262

Source: COCI 2012/2013, contest #1 