import java.io.*;
    import java.util.*;
    import java.math.*;
    import java.lang.*;
     
     //@Manan Parmar

    public class Main implements Runnable {


        public void run() {
            
            InputReader sc = new InputReader(System.in);
            PrintWriter out = new PrintWriter(System.out);
            
            String s=sc.next();
            if(s.charAt(s.length()-1)!='s')
                s=s+"s";
            else
                s=s+"es";
            out.println(s);
            out.close();
        }
     

    //========================================================================
        boolean check(char a,char b)
        {
            if(a==b)
                return true;
            else
                return false;
        }
        long binarySearch(long arr[], long x) 
        { 
            int l = 0, r = arr.length - 1,q=0; 
            while (l<=r) { 
                int m = l + (r - l) / 2; 
                if (arr[l] >=x) 
                {
                    q=1;
                    return l; 
                }
                if (arr[m] < x) 
                    l=m+1; 
                else
                    r=m;
            } 
            return -1;
        }

        static class InputReader {
            private InputStream stream;
            private byte[] buf = new byte[1024];
            private int curChar;
            private int numChars;
            private SpaceCharFilter filter;
            private BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
     
            public InputReader(InputStream stream) {
                this.stream = stream;
            }
           
            public int read() {
                if (numChars==-1)
                    throw new InputMismatchException();
               
                if (curChar >= numChars) {
                    curChar = 0;
                    try {
                        numChars = stream.read(buf);
                    }
                    catch (IOException e) {
                        throw new InputMismatchException();
                    }
                   
                    if(numChars <= 0)              
                        return -1;
                }
                return buf[curChar++];
            }
         
            public String nextLine() {
                String str = "";
                try {
                    str = br.readLine();
                }
                catch (IOException e) {
                    e.printStackTrace();
                }
                return str;
            }
            public int nextInt() {
                int c = read();
               
                while(isSpaceChar(c))
                    c = read();
               
                int sgn = 1;
               
                if (c == '-') {
                    sgn = -1;
                    c = read();
                }
               
                int res = 0;
                do {
                    if(c<'0'||c>'9')
                        throw new InputMismatchException();
                    res *= 10;
                    res += c - '0';
                    c = read();
                }
                while (!isSpaceChar(c));
               
                return res * sgn;
            }
           
            public long nextLong() {
                int c = read();
                while (isSpaceChar(c))
                    c = read();
                int sgn = 1;
                if (c == '-') {
                    sgn = -1;
                    c = read();
                }
                long res = 0;
               
                do {
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res *= 10;
                    res += c - '0';
                    c = read();
                }
                while (!isSpaceChar(c));
                    return res * sgn;
            }
           
            public double nextDouble() {
                int c = read();
                while (isSpaceChar(c))
                    c = read();
                int sgn = 1;
                if (c == '-') {
                    sgn = -1;
                    c = read();
                }
                double res = 0;
                while (!isSpaceChar(c) && c != '.') {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res *= 10;
                    res += c - '0';
                    c = read();
                }
                if (c == '.') {
                    c = read();
                    double m = 1;
                    while (!isSpaceChar(c)) {
                        if (c == 'e' || c == 'E')
                            return res * Math.pow(10, nextInt());
                        if (c < '0' || c > '9')
                            throw new InputMismatchException();
                        m /= 10;
                        res += (c - '0') * m;
                        c = read();
                    }
                }
                return res * sgn;
            }
           
            public String readString() {
                int c = read();
                while (isSpaceChar(c))
                    c = read();
                StringBuilder res = new StringBuilder();
                do {
                    res.appendCodePoint(c);
                    c = read();
                }
                while (!isSpaceChar(c));
               
                return res.toString();
            }
         
            public boolean isSpaceChar(int c) {
                if (filter != null)
                    return filter.isSpaceChar(c);
                return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
            }
         
            public String next() {
                return readString();
            }
           
            public interface SpaceCharFilter {
                public boolean isSpaceChar(int ch);
            }
        }

        public static void main(String args[]) throws Exception {
            new Thread(null, new Main(),"Main",1<<27).start();
        }
    }


Measured memory_bytes: 36612