#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp> 
// #include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
// using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
 
typedef pair<ll, ll> pl;
typedef pair<ld,ld> pd;
typedef vector<ll> vl;
// typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
 
 
#define G(x) ll x; cin >> x;
#define F(i, l, r) for (ll i = l; i < (r); ++i)
#define all(a) begin(a), end(a)
#define K first
#define V second
#define OK(i,j) i >= 0 && i < n && j >= 0 && j < m
 
#define NN 2505
#define MM 5005
#define MOD 1000007

void solve() {

    ld p;
    cin >> p;

    ld q = 1.0 - p;
    bool ok = 0;
    ld ans = 1e9;
    ll num = -1;
    for(ll N = 2; N <= 16; N++) {
        ld P = pow(q,N);
        ld X = P + ((ld)N)*(1 - P);
        if(X < (ld)N) {
            ok = 1;
            if(X < ans*((ld)N)) {
                ans = X/((ld)N);
                num = N;
            }
        }
    }

    if(!ok) cout << 1 << '\n';
    else cout << num << '\n';

}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cout << fixed << setprecision(10);

    solve();

    return 0;

}