#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define vtpl(x,y,z) vector<tuple<x,y,z>>
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={0,1,0,-1,1,1,-1,-1,0};
const ll dx[9]={1,0,-1,0,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

int main(){
    ll n,a,b;cin >> n >> a >> b;
    vvl dp(100000,vl(2));
    dp[0][0]=-b;dp[0][1]=b;
    rep(i,100000-1){
        dp[i+1][0]=min(dp[i][0]+a-b,dp[i][1]-a-b);
        dp[i+1][1]=min(dp[i][0]-a+b,dp[i][1]+a+b);
    }
    if(100000>n){
        cout << min(dp[n-1][0],dp[n-1][1]) << endl;return 0;
    }
    else{
        ll x=(n-1)%6;
        ll dif=dp[606+x][0]-dp[600+x][0];
        ll ans=(n-1-(600+x))/6*dif+dp[600+x][0];
        ll ep=dp[606+x][1]-dp[600+x][1];
        ll ret=(n-1-(600+x))/6*ep+dp[600+x][1];
        cout << min(ans,ret) << endl;
    }
}