#include<stdio.h>

#include<algorithm>

#include<iostream>

#include<vector>

#include<stack>

#include<set>

#include<queue>

#include<cstring>

#define inf 0x3f3f3f3f

#define ll long long

using namespace std;

int dp[];

int main()

{

    memset(dp,-,sizeof(dp));

    dp[]=;

    int a,b,ans=;

    scanf("%d%d",&a,&b);

    for(int i=;i<;i++)

    {

        if(i-a>= && dp[i-a]!=-)

            dp[i]=;

        else if(i-b>= && dp[i-b]!=-)

            dp[i]=;

        else

            ans=max(ans,i);

    }

    printf("%d\n",ans);

    return ;

}