Codeforces 732A.Buy a Shovel

链接http://codeforces.com/problemset/problem/732/A

#include<stdio.h>#include<iostream>using namespace std;int main(){    int k,r;    cin>>k>>r;    int i=1;    for(;;i++){        if((i*k%10==0)||(i*k-r)%10==0)            break;          }    printf("%d\n",i);    return 0;}