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#include <iostream>
#include <set>
#include <map>
#include <vector>
#include <algorithm>

using namespace std;

#define li long long

li phi(li n) {
	li result = n;
	for (li i = 2; i * i <= n; ++i)
		if (n % i == 0) {
			while (n % i == 0)
				n /= i;
			result -= result / i;
		}
	if (n > 1)
		result -= result / n;
	return result;
}
int main() {
	li a, b;
	cin >> a >> b;
	li ans = 0;
	for (li i = a; i <= b; i++) {
		ans += phi(i);
	}
	cout << ans;
	return 0;
}