easy

#include<bits/stdc++.h>
using namespace std;
int a,b,c,nex;
set<int> vis;
int main(){
    ios::sync_with_stdio(0),cin.tie(nullptr),cout.tie(nullptr);
    cin>>a>>b>>c;
    queue<int> q;
    q.push(1);
    vis.insert(1);
    while(!q.empty()){
        int now=q.front();
        q.pop();
        nex=now-1;
        if (!vis.count(nex)){
            q.push(nex);
            vis.insert(nex);
        }
        if (nex==a*b*c)return cout<<nex,0;
        nex=now+1;
        if (!vis.count(nex)){
            q.push(nex);
            vis.insert(nex);
        }
        if (nex==a*b*c)return cout<<nex,0;
        nex=now<<1;
        if (!vis.count(nex)){
            q.push(nex);
            vis.insert(nex);
        }
        if (nex==a*b*c)return cout<<nex,0;
    }
    return 0;
}