#include<iostream>
using namespace std;
int a[1000000],m,n,min_,max_,res;
int main(){
cin>>m>>n;
min_ = m<n?m:n;
max_ = m<n?n:m;
a[0] = 1;
for(int i=min_;i<=m*n;i++){
if(a[i-min_ ]) a[i] =1;
else if(i>=max_ && a[i-max_ ] ) a[i] = 1;
else res = i;
}
cout<<res<<endl;
return 0;
}