#include <bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
const double PI = acos(-1);
template <class T>
constexpr T INF() {
  return ::std::numeric_limits<T>::max();
}
template <class T>
constexpr T HINF() {
  return INF<T>() / 2;
}
template <typename T_char>
T_char TL(T_char cX) {
  return tolower(cX);
};
template <typename T_char>
T_char TU(T_char cX) {
  return toupper(cX);
};
const int vy[] = {-1, -1, -1, 0, 1, 1, 1, 0},
          vx[] = {-1, 0, 1, 1, 1, 0, -1, -1};
const int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
int popcnt(unsigned long long n) {
  int cnt = 0;
  for (int i = 0; i < 64; i++)
    if ((n >> i) & 1) cnt++;
  return cnt;
}
int d_sum(LL n) {
  int ret = 0;
  while (n > 0) {
    ret += n % 10;
    n /= 10;
  }
  return ret;
}
int d_cnt(LL n) {
  int ret = 0;
  while (n > 0) {
    ret++;
    n /= 10;
  }
  return ret;
}
LL gcd(LL a, LL b) {
  if (b == 0) return a;
  return gcd(b, a % b);
};
LL lcm(LL a, LL b) {
  LL g = gcd(a, b);
  return a / g * b;
};
LL n;
int main() {
  cin >> n;
  LL ans = HINF<LL>();
  for (LL i = 1; i <= sqrt(n + 1); i++) {
    if (n % i == 0) {
      ans = min(ans, i + n / i - 2);
    }
  }
  cout << ans << endl;
}
