Buggy python submission (verdict: Runtime Error):
'''
Name: Devansh
Username: singhdevansh
Github: https://github.com/Devansh3712
'''

import os
import sys
import math
from itertools import *
from io import BytesIO, IOBase
from collections import *

#<fast I/O>
BUFSIZE = 8192

class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")

sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
#</fast I/O>

#<template>
mod=(10**9)+7
pi=3.14159265358979323846264338327950

def i1():	#int(input())
	return int(sys.stdin.readline())

def sf():	#input()
	return sys.stdin.readline()

def mi():	#map(int(input()))
	return map(int,sys.stdin.readline().split())

def arr():	#list(map(int,input().split()))
	return list(map(int,sys.stdin.readline().split()))

def pf(ans): #print(x)
	return sys.stdout.write(str(ans)+"\n")

def gcd(a,b):
	if a==0:
		return b
	elif b==0:
		return a
	if a>b:
		return gcd(a%b,b)
	else:
		return gcd(a,b%a)

def lcm(a,b):
	return (a*b)//gcd(a,b)
#</template>

#<solve>
def solve():
	s=input()
	if s[-1]='s':
		print(s+'es')
	else:
		print(s+'s')
solve()
#</solve>

#<solution>
# tc=i1()
# for t in range (tc):
# 	solve()
#<solution>

Fixed submission:
'''
Name: Devansh
Username: singhdevansh
Github: https://github.com/Devansh3712
'''

import os
import sys
import math
from itertools import *
from io import BytesIO, IOBase
from collections import *

#<fast I/O>
BUFSIZE = 8192

class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")

sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
#</fast I/O>

#<template>
mod=(10**9)+7
pi=3.14159265358979323846264338327950

def i1():	#int(input())
	return int(sys.stdin.readline())

def sf():	#input()
	return sys.stdin.readline()

def mi():	#map(int(input()))
	return map(int,sys.stdin.readline().split())

def arr():	#list(map(int,input().split()))
	return list(map(int,sys.stdin.readline().split()))

def pf(ans): #print(x)
	return sys.stdout.write(str(ans)+"\n")

def gcd(a,b):
	if a==0:
		return b
	elif b==0:
		return a
	if a>b:
		return gcd(a%b,b)
	else:
		return gcd(a,b%a)

def lcm(a,b):
	return (a*b)//gcd(a,b)
#</template>


#<solve>
def solve():
	s=input()
	if s[-1]=='s':
		print(s+'es')
	else:
		print(s+'s')
solve()
#</solve>

#<solution>
# tc=i1()
# for t in range (tc):
# 	solve()
#<solution>

Buggy python submission (verdict: Runtime Error):
'''
Name: Devansh
Username: singhdevansh
Github: https://github.com/Devansh3712
'''

import os
import sys
import math
from itertools import *
from io import BytesIO, IOBase
from collections import *

#<fast I/O>
BUFSIZE = 8192

class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")

sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
#</fast I/O>

#<template>
mod=(10**9)+7
pi=3.14159265358979323846264338327950

def i1():	#int(input())
	return int(sys.stdin.readline())

def sf():	#input()
	return sys.stdin.readline()

def mi():	#map(int(input()))
	return map(int,sys.stdin.readline().split())

def arr():	#list(map(int,input().split()))
	return list(map(int,sys.stdin.readline().split()))

def pf(ans): #print(x)
	return sys.stdout.write(str(ans)+"\n")

def gcd(a,b):
	if a==0:
		return b
	elif b==0:
		return a
	if a>b:
		return gcd(a%b,b)
	else:
		return gcd(a,b%a)

def lcm(a,b):
	return (a*b)//gcd(a,b)
#</template>

#<testcases>
#sys.stdin=open('input.txt','r')
#sys.stdout=open('output.txt','w')
#</testcases>

#<solve>
def solve():
	s=input()
	if s[-1]=s:
		print(s+'es')
	else:
		print(s+'s')
solve()
#</solve>

#<solution>
# tc=i1()
# for t in range (tc):
# 	solve()
#<solution>

Fixed submission:
'''
Name: Devansh
Username: singhdevansh
Github: https://github.com/Devansh3712
'''

import os
import sys
import math
from itertools import *
from io import BytesIO, IOBase
from collections import *

#<fast I/O>
BUFSIZE = 8192

class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")

sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
#</fast I/O>

#<template>
mod=(10**9)+7
pi=3.14159265358979323846264338327950

def i1():	#int(input())
	return int(sys.stdin.readline())

def sf():	#input()
	return sys.stdin.readline()

def mi():	#map(int(input()))
	return map(int,sys.stdin.readline().split())

def arr():	#list(map(int,input().split()))
	return list(map(int,sys.stdin.readline().split()))

def pf(ans): #print(x)
	return sys.stdout.write(str(ans)+"\n")

def gcd(a,b):
	if a==0:
		return b
	elif b==0:
		return a
	if a>b:
		return gcd(a%b,b)
	else:
		return gcd(a,b%a)

def lcm(a,b):
	return (a*b)//gcd(a,b)
#</template>


#<solve>
def solve():
	s=input()
	if s[-1]=='s':
		print(s+'es')
	else:
		print(s+'s')
solve()
#</solve>

#<solution>
# tc=i1()
# for t in range (tc):
# 	solve()
#<solution>