rectangle

#include<bits/stdc++.h>
#define FILE "MATRIX"
using namespace std;

typedef unsigned long long ll;

const ll inf = 1e10;

ll getRect(ll size){
    if (!size) return 0;
    if (size == 1) return 1;
    if (size % 2 == 0) return size / 2 * size;
    ll B = (size + 1) / 2, S = size - B;
    return B * B + S * S;
}

ll getEven(ll lim){
    ll d = 1, c = inf / 2, ans = c;
    while (d <= c){
        ll mid = (d + c) / 2;
        ll xSize = mid - 1;
        ll num = 4LL * getRect(xSize);
        if (num >= lim) ans = mid * 2, c = mid - 1;
        else d = mid + 1;
    }
    return ans;
}

ll getOdd(ll lim){
    ll d = 0, c = (inf - 2 ) / 2, ans = c;
    while (d <= c){
        ll mid = (d + c) / 2;
        if (getRect(mid * 2 + 1) >= lim) ans = mid * 2 + 1, c = mid - 1;
        else d = mid + 1;
    }
    return ans;
}

main(){
    freopen(FILE".inp", "r", stdin);
    freopen(FILE".out", "w", stdout);
    ll n;
    cin >> n;
    if (n <= 1) {cout << n; return 0;}
    if (n == 3) { cout << 5; return 0;}
    ll ans = min(getEven(n), getOdd(n));
    cout << ans << '\n';
}