import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int max = 0;
        for (int i = 1; i <= x; i++) {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        }
        System.out.println(max);
    }

} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int max = 0;
        for (int i = 1; i <= x; i++) {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        }
        System.out.println(max);
    }

} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int max = 0;
        for (int i = 1; i <= x; i++) {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        }
        System.out.println(max);
    } main {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int max = 0;
        for (int i = 1; i <= x; i++) {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        }
        System.out.println(max);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc int max = 0; max 0 for (int i = 1; i <= x; i++) {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        } int i = 1; int i = 1; i 1 i <= x i x i++ i++ i {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        } {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        } for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            } int j = 2; int j = 2; j 2 j <= 10 j 10 j++ j++ j {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            } {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            } int num = (int) Math.pow(i, j); num (int) Math.pow(i, j) Math.pow Math i j if (num > x) {
                    break;
                } num > x num x {
                    break;
                } break; if (num > max) {
                    max = num;
                } num > max num max {
                    max = num;
                } max = num max num System.out.println(max) System.out.println System.out System System.out max String[] args args public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int max = 0;
        for (int i = 1; i <= x; i++) {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        }
        System.out.println(max);
    }

} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int max = 0;
        for (int i = 1; i <= x; i++) {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        }
        System.out.println(max);
    }

} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int max = 0;
        for (int i = 1; i <= x; i++) {
            for (int j = 2; j <= 10; j++) {
                int num = (int) Math.pow(i, j);
                if (num > x) {
                    break;
                }
                if (num > max) {
                    max = num;
                }
            }
        }
        System.out.println(max);
    }

}
