include <bits/stdc++.h>

using namespace std;

int getSumOfDigits(int number) { int sum = 0; while (number > 0) { sum += number % 10; number /= 10; } return sum; }

int main() { int m, n; cin >> m >> n;

int minSum = getSumOfDigits(m);
int count = 1;

for (int num = m + 1; num <= n; num++) {
    int sum = getSumOfDigits(num);
    if (sum < minSum) {
        minSum = sum;
        count = 1;
    } else if (sum == minSum) {
        count++;
    }
}

cout << count << endl;

return 0;

}

include<stdio.h>

include<map>

using namespace std; bool OK(int n,int m, int d){ return (m <= d and d <= n); } int give_digits(int n){ int res = 0; while(n > 0){ res += n % 10; n /= 10; }

  return res;

} int comput(int m, int n){ int res = 0; if(m == n){ return 1; }else{ if(OK(n,m,1)) ++res; if(OK(n,m,10)) ++res; if(OK(n,m,100)) ++res; if(OK(n,m,1000)) ++res; if(OK(n,m,1e4)) ++res; if(OK(n,m,1e5)) ++res; if(OK(n,m,1e6)) ++res; if(res) return res; } if(!res){ map<int,int> mp; for(int i = m; i <= n; ++i){ mp[give_digits(i)]++; } return mp.begin()->second; } } int main(){ int m, n; scanf("%d %d",&m,&n); printf("%d\n",comput(m,n)); puts(" "); return 0; }