#include <bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> P;
int INF = 1e16+7;
int mod = 1e9+7;
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
signed main() {
    int A;
    cin >> A;
    int N = A;
    int ans = INF;
    int cnt = 0;
    int pow = 1;
    while (true) {
        cnt++;
        if((N+1)/2 <= pow) {
            break;
        }
        pow*=2;
    }
    ans = min(ans,2*cnt);
    cnt = 0;
    pow = 1;
    N = A;
    while (true) {
        cnt++;
        if((N+2)/3 <= pow) {
            break;
        }
        pow*=3;
    }
    ans = min(ans,3*cnt);
    cnt = 0;
    pow = 1;
    while (true) {
        cnt++;
        if((N+4)/5 <= pow) {
            break;
        }
        pow*=5;
    }
    cout << min(ans,5*cnt) << endl;
}