#include <bits/stdc++.h>
#include <unistd.h>
 
using namespace std;
 
typedef long long ll;
typedef pair<ll,ll> P;
typedef pair<P, ll> T;
 
long long int INF = 1e17;
const ll fact_table = 800008;
double Pi = 3.1415926535897932384626;

priority_queue <ll> pql;
priority_queue <P> pqp;
//big priority queue
priority_queue <ll,vector<ll>,greater<ll> > pqls;
// priority_queue <P,vector<P>,greater<P> > pqps;
//small priority queue
//top pop
 
ll dx[8]={1,0,-1,0,1,1,-1,-1};
ll dy[8]={0,1,0,-1,1,-1,-1,1};
char dir[] = "DRUL";
//↓,→,↑,←
 
 
#define p(x) cout<<x<<"\n";
#define el cout<<endl;
#define pe(x) cout<<(x)<<" ";
#define ps(x) cout<<fixed<<setprecision(25)<<x<<endl;
#define pu(x) cout<<(x);
#define pb push_back
// #define lb lower_bound
#define ub upper_bound
#define CLEAR(a) a = decltype(a)(); 
#define pc(x) cout << x << ",";
 
 
ll mod = 998244353;
//ll mod = 1000000007;
 
ll rui(ll number1,ll number2){
 
    if(number2 == 0){
        return 1;
    }else{
        ll number3 = rui(number1,number2 / 2);
        number3 *= number3;
        number3 %= mod;
        if(number2%2==1){
            number3 *= number1;
            number3 %= mod;
        }
        return number3;
    }
}
ll gcd(ll number1,ll number2){
 
    if(number1 > number2){
        swap(number1,number2);
    }
    if(number1 == 0 || number1 == number2){
        return number2;
    }else{
        return gcd(number2 % number1,number1);
    }
}
void YES(bool condition){
 
    if(condition){
        p("YES");
    }else{
        p("NO");
    }
    return;
}
void Yes(bool condition){
 
    if(condition){
        p("Yes");
    }else{
        p("No");
    }
    return;
}
 
/*
ll fact[fact_table + 5],rfact[fact_table + 5];
 
 
void c3_init(){
    fact[0] = rfact[0] = 1;
    for(ll i=1; i<=fact_table; i++){
        fact[i] = (fact[i-1]*i) % mod;
    }
    rfact[fact_table] = rui(fact[fact_table],mod - 2);
    for(ll i=fact_table; i>=1; i--){
       rfact[i-1] = rfact[i] * i;
       rfact[i-1] %= mod;
    }
    return;}
ll c3(ll n,ll r){
    return (((fact[n] * rfact[r]) % mod ) * rfact[n-r]) % mod;}
*/

ll n,m,num,sum,a,b,c,d,e,h,r,l,q;
ll k;
ll query[500005];


void check(){
    return;
}

ll mypow(ll n, ll exp){
    if(exp == 0){
        return 1ll;
    }else{
        if(exp % 2 == 1){
            return n * mypow(n, exp - 1);
        }else{
            ll tmp = mypow(n, exp / 2);
            return tmp * tmp;
        }
    }
}

int main(){
    cin >> n >> a;
    ll ans = n;
    for(ll i=2;i<50;i++){
        ll maisu = i;
        ll tmp = (maisu - 1) * a;
        ll norm;
        for(ll j=1;;j++){
            ll res = mypow(j, maisu);
            if(res >= n) {
                norm = j - 1;
                break;
            }
        }
        for(ll j=0;j<=maisu;j++){
            ll res = mypow(norm, maisu - j) * mypow(norm + 1, j);
            if(res >= n){
                /*
                for(ll k=0;k<j;k++){
                    pe(norm);
                }
                for(ll k=j;k<maisu;k++){
                    pe(norm + 1);
                }
                el;
                */
                ans = min(ans, tmp + norm * (maisu - j) + (norm + 1) * j);
                break;
            }
        }
    }
    p(ans);
    return 0;
}


















Measured memory_bytes: 256