#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
#include <math.h>
#include <string>
#include <algorithm>
using namespace std;
int k, r;
int ans;
int main() {
scanf("%d %d", &k, &r);
for (int i = 1;i <= 10;++i) {
int tot = i*k;
int re = tot % 10;
if (re == r||re==0) {
printf("%d\n", i);
break;
}
}
return 0;
}