#include<bits/stdc++.h>
using namespace std;

int main(){
	int a, b, s = 0;
	cin >> a >> b;
	for (int i = a; i <= b; i++){
		int cnt = 0, cnt2 = 0;
		while (i > 0){
			cnt += i % 10;
			i /= 10;
			cnt++;
		}
		for(int j = i; j >= 0; j--){
			cnt2 += j;
		}
		if (cnt = cnt2) s++;
	}
	cout << s;
	return 0;
}