import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.stream.LongStream;

public class Main {

    public static void main(String[] args) throws Exception {
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(System.in))) {
            long N = readLong(reader);

            long[] divisors = divisor(N);

            long distance = Long.MAX_VALUE;
            for (long d : divisors) {
                distance = Math.min(distance, d + N / d);
            }

            System.out.println(distance - 2);
        }
    }

    public static long[] divisor(long N) {
        long[] array1 = LongStream.rangeClosed(1, (long) Math.sqrt(N)).filter(n -> N % n == 0).toArray();
        LongStream s2 = Arrays.stream(array1).map(n -> N / n);
        return LongStream.concat(Arrays.stream(array1), s2).distinct().sorted().toArray();
    }

    public static String readString(BufferedReader reader) throws Exception {
        return reader.readLine();
    }

    public static int readInt(BufferedReader reader) throws Exception {
        return Integer.parseInt(reader.readLine());
    }

    public static long readLong(BufferedReader reader) throws Exception {
        return Long.parseLong(reader.readLine());
    }

    public static double readDouble(BufferedReader reader) throws Exception {
        return Double.parseDouble(reader.readLine());
    }

    public static String[] readStringArray(BufferedReader reader) throws Exception {
        return reader.readLine().split(" ");
    }

    public static int[] readIntArray(BufferedReader reader) throws Exception {
        String[] str = reader.readLine().split(" ");
        int[] array = new int[str.length];
        for (int i = 0; i < str.length; i++) {
            array[i] = Integer.parseInt(str[i]);
        }
        return array;
    }

    public static long[] readLongArray(BufferedReader reader) throws Exception {
        String[] str = reader.readLine().split(" ");
        long[] array = new long[str.length];
        for (int i = 0; i < str.length; i++) {
            array[i] = Long.parseLong(str[i]);
        }
        return array;
    }

    public static double[] readDoubleArray(BufferedReader reader) throws Exception {
        String[] str = reader.readLine().split(" ");
        double[] array = new double[str.length];
        for (int i = 0; i < str.length; i++) {
            array[i] = Double.parseDouble(str[i]);
        }
        return array;
    }

    public static int[][] readIntMatrix(BufferedReader reader, int N) throws Exception {
        int[][] matrix = new int[N][];
        for (int i = 0; i < N; i++) {
            matrix[i] = readIntArray(reader);
        }
        return matrix;
    }

    public static long[][] readLongMatrix(BufferedReader reader, int N) throws Exception {
        long[][] matrix = new long[N][];
        for (int i = 0; i < N; i++) {
            matrix[i] = readLongArray(reader);
        }
        return matrix;
    }

    public static double[][] readDoubleMatrix(BufferedReader reader, int N) throws Exception {
        double[][] matrix = new double[N][];
        for (int i = 0; i < N; i++) {
            matrix[i] = readDoubleArray(reader);
        }
        return matrix;
    }

    public static int[] extractArray(int[][] matrix, int index) {
        int[] array = new int[matrix.length];
        for (int i = 0; i < matrix.length; i++) {
            array[i] = matrix[i][index];
        }
        return array;
    }

    public static long[] extractArray(long[][] matrix, int index) {
        long[] array = new long[matrix.length];
        for (int i = 0; i < matrix.length; i++) {
            array[i] = matrix[i][index];
        }
        return array;
    }

    public static double[] extractArray(double[][] matrix, int index) {
        double[] array = new double[matrix.length];
        for (int i = 0; i < matrix.length; i++) {
            array[i] = matrix[i][index];
        }
        return array;
    }

}


Measured memory_bytes: 27988