import java.util.Arrays;

public class Euler70 {
    public static void main(String[] args) {
        int limit = 10_000_000;
        int[] phi = new int[limit];
        for (int i = 0; i < limit; i++)
            phi[i] = i;
        for (int i = 2; i < limit; i++)
            if (phi[i] == i)
                for (int j = i; j < limit; j += i)
                    phi[j] -= phi[j] / i;
        int bestN = -1;
        double bestRatio = Double.MAX_VALUE;
        for (int n = 2; n < limit; n++) {
            char[] a = Integer.toString(n).toCharArray(), b = Integer.toString(phi[n]).toCharArray();
            Arrays.sort(a);
            Arrays.sort(b);
            if (Arrays.equals(a, b)) {
                double ratio = (double) n / phi[n];
                if (ratio < bestRatio) {
                    bestRatio = ratio;
                    bestN = n;
                }
            }
        }
        System.out.println(bestN);
    }
}