public class Euler686 {
    public static String solve() {
        int n = 678910;

        long SCALE = 1000000000000000000L;
        long alpha = 301029995663981195L;
        long lo = 89905111439397916L;
        long hi = 93421685162250260L;

        long x = 0;
        int cnt = 0;
        long j = 0;

        while (cnt < n) {
            j++;
            x += alpha;
            if (x >= SCALE) {
                x -= SCALE;
                if (x >= lo && x < hi) {
                    cnt++;
                }
            }
        }

        return Long.toString(j);
    }

    public static void main(String[] args) {
        System.out.println(solve());
    }
}