import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.InputMismatchException;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

public class Main {
    void solve(MyScanner in, MyWriter out) {
        int n = in.nextInt();
        var sieve = new EratosthenesSieve(n);
        long ans = 0;
        for (int c = 1; c < n; c++) {
            List<PrimeFactor> pfs = sieve.factorize(n - c);
            long d = 1;
            for (PrimeFactor pf : pfs) {
                d *= pf.exponent + 1;
            }
            ans += d;
        }
        out.println(ans);
    }
    static final class EratosthenesSieve {
        private final int[] minPrimes;

        EratosthenesSieve(int maxN) {
            if (maxN < 2) {
                this.minPrimes = new int[0];
            } else {
                int[] a = new int[maxN + 1];
                for (int i = 2; i <= maxN; i++) {
                    if (a[i] != 0) {
                        continue;
                    }
                    a[i] = i;
                    for (long j = (long)i * i; j <= maxN; j += i) {
                        if (a[(int)j] == 0) {
                            a[(int)j] = i;
                        }
                    }
                }
                this.minPrimes = a;
            }
        }
        boolean isPrimeNumber(int n) {
            if (n >= minPrimes.length) {
                throw new IllegalArgumentException();
            }
            if (n < 2) {
                return false;
            }
            return minPrimes[n] == n;
        }
        List<PrimeFactor> factorize(int n) {
            if (n >= minPrimes.length) {
                throw new IllegalArgumentException();
            }
            if (n < 2) {
                return Collections.emptyList();
            }
            List<PrimeFactor> result = new ArrayList<>();
            do {
                int prime = minPrimes[n];
                int exponent = 0;
                do {
                    n /= prime;
                    exponent++;
                } while (minPrimes[n] == prime);

                result.add(new PrimeFactor(prime, exponent));
            } while (n != 1);

            return result;
        }
        List<List<PrimeFactor>> factorize(int[] n) {
            List<List<PrimeFactor>> result = new ArrayList<>(n.length);
            for (int number : n) {
                result.add(factorize(number));
            }
            return result;
        }
    }
    static final class PrimeFactor {
        final long primeNumber;
        final long exponent;

        PrimeFactor(long primeNumber, long exponent) {
            if (primeNumber <= 1) {
                throw new IllegalArgumentException();
            }
            if (exponent < 0) {
                throw new IllegalArgumentException();
            }
            this.primeNumber = primeNumber;
            this.exponent = exponent;
        }
        static List<PrimeFactor> factorize(long n) {
            if (n < 2) {
                return Collections.emptyList();
            }
            List<PrimeFactor> result = new ArrayList<>();
            for (long i = 2; i * i <= n; i += (i == 2 ? 1 : 2)) {
                if (n % i != 0) {
                    continue;
                }
                long exp = 1;
                n /= i;
                for (; n % i == 0; n /= i) {
                    exp++;
                }
                result.add(new PrimeFactor(i, exp));
            }
            if (n != 1) {
                result.add(new PrimeFactor(n, 1));
            }
            return result;
        }
    }
    public static void main(String[] args) {
        MyWriter w = new MyWriter(System.out);
        new Main().solve(new MyScanner(System.in), w);
        w.flush();
    }
    static final class MyScanner {
        static final int BUFFER_SIZE = 8192;
        private final InputStream in;
        private final byte[] buffer = new byte[BUFFER_SIZE];
        private int point;
        private int readLength;

        MyScanner(InputStream in) {
            this.in = in;
        }
        private int readByte() {
            if (point < readLength) {
                int result = buffer[point];
                point += 1;
                return result;
            }
            try {
                readLength = in.read(buffer);
            } catch (IOException e) {
                throw new AssertionError(null, e);
            }
            if (readLength == -1) {
                return -1;
            }
            point = 1;
            return buffer[0];
        }
        private static boolean isVisibleChar(int c) {
            return 33 <= c && c <= 126;
        }
        char nextChar() {
            int c = readByte();
            while (!(c == -1 || isVisibleChar(c))) {
                c = readByte();
            }
            if (c == -1) {
                throw new NoSuchElementException();
            }
            return (char)c;
        }
        String next() {
            return next(16);
        }
        String next(int n) {
            int c = readByte();
            while (!(c == -1 || isVisibleChar(c))) {
                c = readByte();
            }
            if (c == -1) {
                throw new NoSuchElementException();
            }
            StringBuilder b = new StringBuilder(n);
            do {
                b.append((char)c);
                c = readByte();
            } while (c != -1 && isVisibleChar(c));
            return b.toString();
        }
        long nextLong() {
            int c = readByte();
            while (!(c == -1 || isVisibleChar(c))) {
                c = readByte();
            }
            if (c == -1) {
                throw new NoSuchElementException();
            }
            boolean minus = false;
            long limit = -Long.MAX_VALUE;
            if (c == '-') {
                minus = true;
                limit = Long.MIN_VALUE;
                c = readByte();
            }
            long n = 0L;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                if (n < limit / 10L) {
                    throw new InputMismatchException();
                }
                n *= 10L;
                int digit = c - '0';
                if (n < limit + digit) {
                    throw new InputMismatchException();
                }
                n -= digit;
                c = readByte();
            } while (c != -1 && isVisibleChar(c));
            return minus ? n : -n;
        }
        int nextInt() {
            long n = nextLong();
            if (n < Integer.MIN_VALUE || n > Integer.MAX_VALUE) {
                throw new InputMismatchException();
            }
            return (int)n;
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }
        int[] nextIntArray(int n) {
            int[] result = new int[n];
            for (int i = 0; i < n; i++) {
                result[i] = nextInt();
            }
            return result;
        }
        long[] nextLongArray(int n) {
            long[] result = new long[n];
            for (int i = 0; i < n; i++) {
                result[i] = nextLong();
            }
            return result;
        }
        char[] nextCharArray(int n) {
            char[] result = new char[n];
            for (int i = 0; i < n; i++) {
                result[i] = nextChar();
            }
            return result;
        }
        char[][] next2dCharArray(int h, int w) {
            char[][] result = new char[h][w];
            for (int i = 0; i < h; i++) {
                for (int j = 0; j < w; j++) {
                    result[i][j] = nextChar();
                }
            }
            return result;
        }
        int[][] nextVerticalIntArrays(int arrayCount, int arrayLength) {
            int[][] result = new int[arrayCount][arrayLength];
            for (int i = 0; i < arrayLength; i++) {
                for (int j = 0; j < arrayCount; j++) {
                    result[j][i] = nextInt();
                }
            }
            return result;
        }
        long[][] nextVerticalLongArrays(int arrayCount, int arrayLength) {
            long[][] result = new long[arrayCount][arrayLength];
            for (int i = 0; i < arrayLength; i++) {
                for (int j = 0; j < arrayCount; j++) {
                    result[j][i] = nextLong();
                }
            }
            return result;
        }
        char[][] nextVerticalCharArrays(int arrayCount, int arrayLength) {
            char[][] result = new char[arrayCount][arrayLength];
            for (int i = 0; i < arrayLength; i++) {
                for (int j = 0; j < arrayCount; j++) {
                    result[j][i] = nextChar();
                }
            }
            return result;
        }
        List<String> nextStringList(int n) {
            var result = new ArrayList<String>(n);
            for (int i = 0; i < n; i++) {
                result.add(next());
            }
            return result;
        }
        List<Integer> nextIntList(int n) {
            var result = new ArrayList<Integer>(n);
            for (int i = 0; i < n; i++) {
                result.add(nextInt());
            }
            return result;
        }
        List<Long> nextLongList(int n) {
            var result = new ArrayList<Long>(n);
            for (int i = 0; i < n; i++) {
                result.add(nextLong());
            }
            return result;
        }
    }
    static final class MyWriter extends PrintWriter {
        MyWriter(OutputStream out) {
            super(out);
        }
        void println(int[] x) {
            println(x, " ");
        }
        void println(int[] x, String delimiter) {
            if (x.length > 0) {
                print(x[0]);
                for (int i = 1; i < x.length; i++) {
                    print(delimiter);
                    print(x[i]);
                }
            }
            println();
        }
        void println(long[] x) {
            println(x, " ");
        }
        void println(long[] x, String delimiter) {
            if (x.length > 0) {
                print(x[0]);
                for (int i = 1; i < x.length; i++) {
                    print(delimiter);
                    print(x[i]);
                }
            }
            println();
        }
        void println(Iterable<?> iterable) {
            println(iterable, " ");
        }
        void println(Iterable<?> iterable, String delimiter) {
            Iterator<?> i = iterable.iterator();
            if (i.hasNext()) {
                print(i.next());
                while (i.hasNext()) {
                    print(delimiter);
                    print(i.next());
                }
            }
            println();
        }
        void printLines(int[] x) {
            println(x, System.lineSeparator());
        }
        void printLines(long[] x) {
            println(x, System.lineSeparator());
        }
        void printLines(Iterable<?> iterable) {
            println(iterable, System.lineSeparator());
        }
    }
}


Measured memory_bytes: 55308