#include <bits/stdc++.h>
#define int long long
using namespace std;
int dp[20][10][10][3];
bool ok(int x){
string s = to_string(x); int n = s.size();
for(int i = 0; i < n - 1; i++) if(s[i] == s[i + 1]) return false;
for(int i = 0; i < n - 2; i++) if(s[i] == s[i + 2]) return false;
return true;
}
int count_prefix(int r){
memset(dp, 0, sizeof(dp));
int ans = 0;
for(int i = 0; i < 100; i++) ans += (i <= r) && ok(i);
int pw10 = 100;
for(int x = 0; x < 10; x++){
for(int y = 0; y < 10; y++){
if(x == y) continue;
int val = x + y * 10;
int type = 0; if(val > r % pw10) type = 2; if(val == r % pw10) type = 1;
dp[2][x][y][type]++;
}
}
for(int d = 3; d <= 18; d++){
pw10 *= 10;
for(int x = 0; x < 10; x++){
for(int y = 0; y < 10; y++){
for(int ty = 0; ty < 3; ty++){
for(int z = 0; z < 10; z++){
if(z == x || z == y) continue;
int nty;
if(z > r % pw10 / (pw10 / 10)) nty = 2;
else if(z == r % pw10 / (pw10 / 10)) nty = ty;
else nty = 0;
dp[d][y][z][nty] += dp[d - 1][x][y][ty];
}
}
}
}
for(int x = 0; x < 10; x++){
for(int y = 1; y < 10; y++){
for(int ty = 0; ty < 3; ty++){
if(pw10 - 1 > r && ty == 2) continue;
ans += dp[d][x][y][ty];
}
}
}
}
return ans;
}
int32_t main(){
cin.tie(0); cout.tie(0)->sync_with_stdio(false);
int a, b; cin >> a >> b;
int ans = count_prefix(b) - count_prefix(a - 1);
cout << ans << endl;
}
