import java.util.*;
import java.io.*;

public class Main
{
    public static long mod = 1000000007;
    public static long[] dp = new long[2005];

    public static long DP(int S) {
        if(S == 0) return 1;
        if(dp[S] != -1) return dp[S];
        long ret = 0;
        for(int i=3; i<=S; i++) {
            ret += DP(S - i);
            ret %= mod;
        }

        return dp[S] = ret;
    }

    public static void main(String[] args) throws IOException 
    {
        Reader Scan = new Reader();
        int S = Scan.nextInt();

        for(int i=0; i<=S; i++) dp[i] = -1;

        System.out.println(DP(S));
    }
    
    
    
    
    
    
    
    
    
    static class Reader 
    { 
        final private int BUFFER_SIZE = 1 << 16; 
        private DataInputStream din; 
        private byte[] buffer; 
        private int bufferPointer, bytesRead; 
  
        public Reader() throws IOException
        { 
            din = new DataInputStream(System.in); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public Reader(String file_name) throws IOException 
        { 
            din = new DataInputStream(new FileInputStream(file_name)); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public String readLine() throws IOException 
        { 
            byte[] buf = new byte[64]; // line length 
            int cnt = 0, c; 
            while ((c = read()) != -1) { 
                if (c == '\n') break; 
                buf[cnt++] = (byte) c; 
            } 
            return new String(buf, 0, cnt); 
        } 
  
        public int nextInt() throws IOException 
        { 
            int ret = 0; 
            byte c = read(); 
            while (c <= ' ') c = read(); 
            boolean neg = (c == '-'); 
            if (neg) c = read(); 
            do {ret = ret * 10 + c - '0';}  while ((c = read()) >= '0' && c <= '9'); 
            if (neg) return -ret; 
            return ret; 
        } 
  
        public long nextLong() throws IOException 
        { 
            long ret = 0; 
            byte c = read(); 
            while (c <= ' ') c = read(); 
            boolean neg = (c == '-'); 
            if (neg) c = read(); 
            do { ret = ret * 10 + c - '0'; } while ((c = read()) >= '0' && c <= '9'); 
            if (neg) return -ret; 
            return ret; 
        } 
  
        public double nextDouble() throws IOException 
        { 
            double ret = 0, div = 1; 
            byte c = read(); 
            while (c <= ' ') c = read(); 
            boolean neg = (c == '-'); 
            if (neg) c = read(); 
  
            do { ret = ret * 10 + c - '0'; } 
            while ((c = read()) >= '0' && c <= '9'); 
            if (c == '.') while ((c = read()) >= '0' && c <= '9') ret += (c - '0') / (div *= 10); 
            if (neg) return -ret; 
            return ret; 
        } 
  
        private void fillBuffer() throws IOException 
        { 
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
            if (bytesRead == -1) buffer[0] = -1; 
        } 
  
        private byte read() throws IOException 
        { 
            if (bufferPointer == bytesRead) fillBuffer(); 
            return buffer[bufferPointer++]; 
        } 
  
        public void close() throws IOException 
        { 
            if (din == null) return; 
            din.close(); 
        } 
    } 
}

Measured memory_bytes: 34764