include<iostream>

using namespace std;

int main()
{
long long a , b ;
cin >> a >> b ;
int count = 0;
for ( long long i = a ; i <= b; i++ )
{
int digit = -1 ;
long long num = i ;
bool tm = true;
while ( num != 0 )
{
int digit1 = num % 10;
if ( digit1 == digit)
{
tm = false;
break ;
}
digit = digit1 ;
num /= 10 ;
}
if ( tm == true )
{
count ++ ;
}
}
cout << count;
}