#include<bits/stdc++.h>
using namespace std;
const int M = 1e6;
int candy[M] ;
int main()
{
int a, b;
cin >> a >> b;
for (int i =a; i < M; i+=a)
{
candy[i] = 1;
}
for (int i = b; i < M; i+=b)
{
candy[i] = 1;
}
int res;
for (int i = max(a,b); i < M; i++){
if(candy[i-a]||candy[i-b]){ //可以被这两个组合出来
candy[i]=1;
}
else{
res=i;
}
}
cout<<res<<endl;
return 0;
}