Problem:
 Score : 100 points    Problem Statement There are N children in AtCoder Kindergarten. Mr. Evi will arrange the children in a line, then give 1 candy to the first child in the line, 2 candies to the second child, ..., N candies to the N -th child. How many candies will be necessary in total?      Constraints  1≦N≦100         Input The input is given from Standard Input in the following format:  N       Output Print the necessary number of candies in total.        Sample Input 1 3      Sample Output 1 6  The answer is 1+2+3=6 .       Sample Input 2 10      Sample Output 2 55  The sum of the integers from 1 to 10 is 55 .       Sample Input 3 1      Sample Output 3 1  Only one child. The answer is 1 in this case.

Solution (Python):
N = int(input())

def ame(N):
    total = 0
    for i in range(1, N + 1):
        total += i
    return total
    
print(ame(N))

Solution (Python):
N=int(input())
print(int(N*(N+1)/2))

Solution (Python):
n = int(input())
print(int(n*(n+1)/2))

Solution (Python):
n = int(input())
print(n * (n+1) // 2)

Solution (Python):
n=int(input())

ans=sum([i for i in range(n+1)])

print(ans)

Solution (Python):
N = int(input())
ans = sum([i for i in range(N+1)])
print(ans)

Solution (Python):
N = int(input())
print((1+N)*N//2)

Solution (Python):
k=input()
a=int(k)
b=1
c=0
for j in range(1,a+1):
  c+=j
print(c)

Solution (Python):
N = int(input())

print(sum(range(1, N+1)))

Solution (Python):
N = int(input())
counter = 0
for val in range(N+1):
    counter = counter + int(val)
print(counter)

Solution (Python):
n = int(input())
print((1+n)*n//2)

Solution (Python):

a = int(input())

sum = a * (a+1) / 2
print(int(sum))

Solution (Python):
n = int(input())
print(sum(range(1,n+1)))

Solution (Python):
n = int(input())
count = 0
for i in range(1,n+1):
  count += i
print(count)

Solution (Python):
N = int(input())
print(N*(N+1)//2)

Solution (Python):
N = int(input())
print((N*(N+1))//2)

Solution (Python):
a = int(input())
print(sum(range(1,a+1)))

Solution (Python):
n = int(input())
print(sum(range(n+1)))

Solution (Python):
n = int(input())
c = 0
for i in range(n+1):
    c += i
print(c)

Solution (Python):
n=int(input())
print(int(n*(n+1)/2))

Solution (Python):
N=int(input())
p=0
for i in range(1,N+1):
  p=p+i
print(p)

Solution (Python):
N = int(input())

print(N*(N+1)//2)

Solution (Python):
a = int(input())
answer = 0
for i in range(a+1):
  answer += i
  
print(answer)

Solution (Python):
N = int(input())

t = 0
for i in range(1, N+1):
    t = t + i
print(t)

Solution (Python):
b = int(input())
c = 0
for i in range(b+1):
    c += i
print(c)

Solution (Python):
n = int(input())
c = 0
for i in range(1,n+1):
  c += i
print(c)

Solution (Python):
"""
author : halo2halo
date : 4, Feb, 2020
"""

import sys
import itertools

import numpy as np

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(readline())

print((N+1)*N//2)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())
sum = 0
for i in range(1,N+1):
	sum += i
print(sum)

Solution (Python):
n = int(input())

candy = 0
for index in range(n):
    candy += index + 1
print(str(candy))

Solution (Python):
n = int(input())
print(n * (n+1) // 2)

Solution (Python):
n = int(input())
ret = 0
for i in range(n+1):
    ret += i
print(ret)

Solution (Python):
print(sum([i for i in range((int(input()))+1)]))

Solution (Python):




def main():
    N = int(input())
    result = 0
    for i in range(N + 1):
        result += i
    print(result)


if __name__ == "__main__":
    main()

Solution (Python):


N = int(input())
C = 0
for i in range(N):
    C = C + (i+1)
print(C)

Solution (Python):
a = int(input())
ans = 0
 
for i in range(a):
  i += 1
  ans = ans + i
  
print(ans)

Solution (Python):
print(sum([i for i in range(1, int(input()) + 1)]))

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())
print(N * (N + 1) // 2)

Solution (Python):
N = int(input())

sum = 0

for i in range(N):
    sum += i + 1

print(sum)

Solution (Python):
children = int(input())

candy = 0
for c in range(children):
    candy += (c+1)
  
print(candy)

Solution (Python):
n = int(input())
f = 0
for i in range(n+1):
    f+=i
print(f)

Solution (Python):
N = int(input())

ans = N * (N + 1) // 2

print(ans)

Solution (Python):
N = int(input())

print(int((N+1)*N/2))

Solution (Python):
N = int(input())
print(int((1 / 2) * N * (2 + (N - 1))))

Solution (Python):
n = int(input())

s = 0

for i in range(1, n+1):
  s += i

print(s)

Solution (Python):
n = int(input())
a = 0

for i in range(n):
    a += i+1
print(a)

Solution (Python):
N = int(input())
s = 0
for i in range(1, N+1):
	s += i
print(s)

Solution (Python):
N=int(input())
print(N*(N+1)//2)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n=int(input())
print(int((1+n)*n/2))

Solution (Python):
n = int(input())
j = 0
for i in range(n+1):
  j = j + i
  
print(j)

Solution (Python):

N=int(input())
s=0
for i in range(N+1):
    s += i
print(s)

Solution (Python):
import sys
import numpy as np


n = int(input())

child = np.arange(1, n + 1)

print(child.sum())

Solution (Python):
N = int(input())
a=0
for i in range(N+1):
    a = a + i
print(a)

Solution (Python):
def main():
    from sys import stdin, setrecursionlimit
    
    n = int(stdin.readline()[:-1])   
    
    
    
    
    
    
    
    
    
    
    
    print((1+n)*n//2)

if __name__ == '__main__':
    main()

Solution (Python):
n=int(input())
x=0
for i in range(1,n+1):
  x += i
print(x)

Solution (Python):
a=int(input())
print(int((1+a)*a/2))

Solution (Python):
def calc_sum_of_candies(sum_of_children):
    sum_of_candies = 0
    for i in range(sum_of_children+1):
        sum_of_candies = sum_of_candies + i

    return sum_of_candies

if __name__=='__main__':
    sum_of_children = int(input())
    print(calc_sum_of_candies(sum_of_children))

Solution (Python):
N = int(input())

print(sum([i for i in range(1,N + 1)]))

Solution (Python):
N = int(input())
li = []
for i in range (N):
  li.append (1+i)

print(sum(li))

Solution (Python):
N = int(input())

count = 0
for i in range(N):
  count += i + 1

print(count)

Solution (Python):
N = int(input())
print(N*(N+1)//2)

Solution (Python):
count = int(input())
answer = 0
for i in range(1, count + 1):
    answer = answer + i
print(answer)

Solution (Python):
if __name__ == "__main__":
    N = int(input())
    print(sum(range(1, N+1)))

Solution (Python):
N = int(input())

print(sum(list(range(1,N+1))))

Solution (Python):
import sys
input = sys.stdin.readline
n=int(input())
ans=0
for i in range(1,n+1):
    ans+=i
print(ans)

Solution (Python):



N = int(input())

sum = 0

for i in range(N):
    i = i + 1
    sum = sum + i

print(sum)

Solution (Python):
N=int(input())
s=N*(N+1)/2
print(int(s))

Solution (Python):
N = int(input())

S = N*(N+1)//2

print(S)

Solution (Python):
N = int(input())
print(int(0.5 * (N ** 2 + N)))

Solution (Python):
print(sum(range(1,int(input())+1)))

Solution (Python):
n = int(input())
print(n*(n+1) // 2)

Solution (Python):
import sys
 
N = int(input())
sum = 0
for i in range(N + 1):
  sum += i
print(str(sum))

Solution (Python):
n=int(input())
ans=0
for i in range(n):
    ans+=(i+1)
print(ans)

Solution (Python):
N = int(input())

ans = 0
for i in range(1, N+1):
  ans += i

print(ans)

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input(), 10)
print(sum([n for n in range(1, N+1)]))

Solution (Python):

N=int(input())
ans=0
for i in range(1,N+1):
    ans+=i
print(ans)

Solution (Python):

n = int(input())
print((n*(n+1))//2)

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())
print(N*(N+1)//2)

Solution (Python):
N = int(input())
print((N*(N+1))//2)

Solution (Python):
N = int(input())
print((N*(N+1))//2)

Solution (Python):
import sys
import math
def i():return int(sys.stdin.readline().replace("\n",""))
def i2():return map(int,sys.stdin.readline().replace("\n","").split())
def s():return str(sys.stdin.readline().replace("\n",""))
def l():return list(sys.stdin.readline().replace("\n",""))
def intl():return [int(k) for k in sys.stdin.readline().replace("\n","").split()]
def lx():return list(map(lambda x:int(x)*-1,sys.stdin.readline().replace("\n","").split()))
def t():return tuple(map(int,sys.stdin.readline().replace("\n","").split()))

if __name__ == "__main__":pass

n = i()
a = [i for i in range(1,n+1)]
print(sum(a))

Solution (Python):
N=int(input())
ans = 0
for i in range(1,N+1):
    ans += i
print(ans)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())

ans = 0
for i in range(1, n + 1):
    ans += i

print(ans)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())
ans = sum(list(range(1,n+1)))
print(ans)

Solution (Python):
s = input()
total = 0
for i in range(int(s)+1):
    total += i
print(total)

Solution (Python):
N = int(input())
print(int((N+1)*N/2))

Solution (Python):
n = int(input())
total = 0
for i in range(n+1):
    total += i
print(total)

Solution (Python):
n = int(input())
t = 0

for i in range(n+1):
	t += i

print(t)

Solution (Python):
def factorial(n):
    if n == 1:
        return 1
    else:
        return n + factorial(n-1)

a = int(input())
print(factorial(a))

Solution (Python):
n = int(input())

ans = 0
for i in range(1, n+1):
    ans += i

print(ans)

Solution (Python):
N = int(input())
if N % 2 == 0:
  r = (N + 1) * N / 2
else:
  r = N * (N - 1) / 2 + N

print(int(r))

Solution (Python):
n = int(input())
sum=0
for i in range(1,n+1):
    sum+=i
print(sum)

Solution (Python):
subin = int(input())
res = int((1+subin) * subin / 2)
print(res)

Solution (Python):
n = int(input())
ans = n * (n+1) / 2
print(int(ans))

Solution (Python):
n = int(input())
print((n*(n+1)) // 2)

Solution (Python):
n = int(input())
ans = n * (n+1) / 2
print(int(ans))

Solution (Python):
n = int(input())
sum = 0

for i in range(1, n + 1):
    sum += i
    
print(sum)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())

result = 0
for i in range(1,n+1):
  result += i

print(result)

Solution (Python):
N = int(input())
print((1+N)*N//2)

Solution (Python):
a = int(input())
print(a*(a+1)//2)

Solution (Python):
n = int(input())
ans = sum(list(range(n, 0, -1)))
print(ans)

Solution (Python):
print(sum([n for n in range(1, int(input())+1)]))

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())
sum = 0
for i in range(N):
    sum+=(i+1)
print(sum)

Solution (Python):
N = int(input())
print(N * (N + 1) // 2)

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
n=int(input())
sum=0
for i in range(n):
  sum+=(i+1)
print(sum)

Solution (Python):
import sys
input = sys.stdin.readline
N = int(input())
print(((1 + N) * N) // 2)

Solution (Python):
enji = int(input())
goukei = 0
for num in range(1,enji):
    goukei = goukei + num
goukei = goukei + enji
print(goukei)

Solution (Python):
N = int(input())
ans = 0
for i in range(1, N+1):
	ans += i
print(ans)

Solution (Python):
a=int(input())
print(a*(a+1)//2)

Solution (Python):
N = int(input())
r=0
for i in range(N):
  r +=i+1
print(r)

Solution (Python):
children = int(input())
total = 0
for i in range(children):
  i += 1
  total += i
print(total)

Solution (Python):
n = int(input())

num = 0
for i in range(n):
  num = num + i + 1
print(num)

Solution (Python):
n=int(input())
a=0
for i in range(n+1):
    a+=i
print(a)

Solution (Python):
n = int(input())

c = 0
for i in range(1, n+1):
   c += i

print(c)

Solution (Python):
n = int(input())
res = 0
for i in range(n+1):
    res += i
print(res)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())
print(int(N * (1 + N) / 2))

Solution (Python):
n = int(input())
ans=0
for i in range(n):
    ans+=1+i
print(ans)

Solution (Python):
n = int(input())

ans = 0

for i in range(n+1):
   ans += i
print(ans)

Solution (Python):
n=int(input());print(n*(n+1)//2)

Solution (Python):
N = int(input())
ans = sum([i for i in range(1, N+1)])
print(ans)

Solution (Python):
n = int(input())
ans = 0
for x in range(n+1):
  ans += x
print(ans)

Solution (Python):
def sigma(n: int) -> int:
    sum = 0
    if n != 1:
        sum += n
        sum += sigma(n-1)
    else:
        sum += n
        return sum

    return sum

n = int(input())
total = sigma(n)
print(total)

Solution (Python):
import math
import fractions

n = int(input())
print(n * (n + 1) // 2)

Solution (Python):
N = int(input())
print(int(N * (N + 1) / 2))

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
print(sum(range(int(input())+1)))

Solution (Python):
N = int(input())
ans = 0
for i in range(1,N+1):
	ans += i
print(ans)

Solution (Python):
def gauss(n):
    ans = int (n * (n + 1) / 2)
    return(ans) 

N = int(input())

print(gauss(N))

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())
print((N+1)*N//2)

Solution (Python):
n = int(input())

print(int(n*(1+n)/2))

Solution (Python):
N = int(input())
print((N+1)*N//2)

Solution (Python):
a = int(input())
s = 0
for i in range(a+1):
  s += i
print(s)

Solution (Python):
n = int(input())

candy = 0

for i in range(1,n+1):
    candy += i

print(candy)

Solution (Python):
n = int(input())
sum=0
for i in range(1,n+1):
	sum+=i
print(sum)

Solution (Python):
N=int(input())
print(int(N * (N + 1) / 2))

Solution (Python):
N = int(input())
a = N*(N+1)//2
print(a)

Solution (Python):
N = int(input())
a = N*(N+1)//2
print(a)

Solution (Python):
N = int(input())
a = N*(N+1)//2
print(a)

Solution (Python):
print(sum(range(1, int(input())+1)))

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):

N = int(input())
print((N+1) * N // 2)

Solution (Python):
n = int(input())
print(int(n/2*(n+1)))

Solution (Python):
n = int(input())

count = 0
for i in range(1, n+1):
    count += i

print(count)

Solution (Python):
n = int(input())
r = n*(n+1)//2
print(r)

Solution (Python):
n=int(input())
counter=0
for i in range(n+1):
  counter+=i

print(counter)

Solution (Python):
N = int(input())
print(int((N+1)*N/2))

Solution (Python):
N = int(input())
print(int((N+1)*N/2))

Solution (Python):
n=int(input())
print(int(n*(n+1)/2))

Solution (Python):

import sys


def main(argv=sys.argv):
  
  n = int(input())
  
  candy_count = 0

  if n == 1:
    candy_count = 1
  else:
    candy_count = (1 + n) * n // 2
    
  print(candy_count)
  
  return 0


if __name__ == '__main__':
  sys.exit(main())

Solution (Python):

import sys

def main(argv=sys.argv):
  
  n = int(input())
  total = 0
  
  for i in range(n+1):
    total += i
  
  print(total)
  
  return 0

if __name__ == '__main__':
  sys.exit(main())

Solution (Python):
n = int(input())
print(int((n + 1) * n / 2))

Solution (Python):
import math
import queue
import bisect
import heapq
import time
import itertools

mod = int(1e9+7)

def swap(a,b):
    return (b,a)

def gcd(a,b): 
    if (a<b):
        a,b = swap(a,b)
    if (b==0):
        return a
    else:
        return gcd(b,a%b)

def divisors(a): 
    divisors = []
    for i in range(1,int(a**0.5)+1):
        if a%i==0:
            divisors.append(i)
            if i!=a//i:
                divisors.append(a//i)
    return divisors

def is_prime(a): 
    if a<2:
        return False
    elif a==2:
        return True
    elif a%2==0:
        return False
    sqrt_num = int(a**0.5)
    for i in range(3,sqrt_num+1,2):
        if a%i==0:
            return False
    return True

def prime_num(a): 
    pn = [2]
    for i in range(3,int(a**0.5),2):
        prime = True
        for j in pn:
            if i%j==0:
                prime = False
                break
        if prime:
            pn.append(i)
    return pn

def main():
    n = int(input())
    ans = 0
    for i in range(n):
        ans += i + 1
    print(ans)
    return

if __name__=='__main__':
    main()

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())
print(n * (n + 1) // 2)

Solution (Python):
a=int(input())
b=0
for i in range(a):
  b+=i+1
print(b)

Solution (Python):
ans = 0
for i in range(1,int(input())+1):
  ans += i
print(ans)

Solution (Python):
n = int(input())

print(int((n+1) * n/2))

Solution (Python):
n = int(input())

print((n + 1)*n//2)

Solution (Python):
N = int(input())
ans = int(N*(N+1)/2)
print(ans)

Solution (Python):


n = int(input())

m = int((n+1) * n / 2)

print(m)

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())

count = 0
for i in range(1, n+1):
    count += i

print(count)

Solution (Python):
A = int(input())
sum = 0
for i in range(1,A+1):
	sum += i
print(str(sum))

Solution (Python):

 
value = int(input())
 
gokei = 0
 
for i in range(value):
    gokei += i + 1
    
print(gokei)

Solution (Python):


n = int(input())
ans = 0

for i in range(1,n+1):
    ans += i

print(ans)

Solution (Python):
N = list(range(1,int(input())+1))

print(sum(N))

Solution (Python):
a = int( input() )

sol = a * ( a + 1 ) // 2 

print( sol )

Solution (Python):
N = int(input())
x = 0
for i in range(1,N+1):
    x = x + i
print(x)

Solution (Python):

N = int(input())

ans = 0
for i in range(N+1):
    ans += i

print(ans)

Solution (Python):
子供の数=int(input())
答え=0
for 飴の数 in range(1,子供の数+1):
  答え+=飴の数
print(答え)

Solution (Python):
n = int(input())
sum = 0
for i in range(1,n+1):
  sum +=i
print(sum)

Solution (Python):
n=int(input())
print((1+n)*n//2)

Solution (Python):
n = int(input())
i = 1
sum = 0
for i in range(1,n + 1):
  sum += i
print(sum)

Solution (Python):
n=int(input())
sum_n=0
for i in range(n+1):
  sum_n+=i
print(sum_n)

Solution (Python):
n=int(input())
ans=0
for i in range(1,n+1):
  ans+=i
print(ans)

Solution (Python):
N = int(input())

n = 0

for i in range(N):
  n += i+1
print(n)

Solution (Python):
n = int(input())
j = 1
k = 0
for i in range(n):
  k += j
  j += 1
print(k)

Solution (Python):
import sys

n = int(sys.stdin.readline().rstrip())

def main():
    ans = (1 + n) * n // 2
    return ans 

if __name__ == '__main__':
    ans = main()
    print(ans)

Solution (Python):
n = int(input())
print((n * (n + 1)) // 2)

Solution (Python):
n=int(input())
k=n*(n+1)/2
print(int(k))

Solution (Python):
a = input()
a=int(a)
ans=0
for i in range(1,a+1):
  ans+=i
print(ans)

Solution (Python):
N = int(input())
print(int(N * (N + 1) / 2))

Solution (Python):
N = int(input())
print(N*(N+1)//2)

Solution (Python):
n = int(input())

ans = 0
for i in range(1, n + 1):
    ans += i

print(ans)

Solution (Python):
n = int(input())

print(int(n * (n + 1) / 2))

Solution (Python):
a=int(input())
b=0
for i in range(a+1):
    b=b+i
print(b)

Solution (Python):
n = int(input())
a = 0
b = 0
while a <= n:
	b = b + a
	a += 1
print(b)

Solution (Python):
N = int(input())

result =0
print(sum([result + i for i in range(1, N+1)]))

Solution (Python):
a = int(input())
print('{:.0f}'.format((a+1)*a/2))

Solution (Python):
N = int(input())

ans = 0

for i in range(1,N+1):
    ans += i
print(ans)

Solution (Python):
N = int(input())
candy = 0
for i in range(N + 1):
    candy += i

print(candy)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n=int(input())
s=0
for i in range(1,n+1):
    s+=i
print(s)

Solution (Python):
n = int(input())
c = 0

for i in range(n + 1):
    c += i
print(c)

Solution (Python):



N = int(input())

R = 0
for i in range(N):
    R += i + 1

print(R)

Solution (Python):
import numpy
n = int(input())

hairetsu = numpy.arange(1, n+1, 1)

print(sum(hairetsu))

Solution (Python):
n = int(input())
ans = 0
for i in range(1,n+1):
    ans += i
print(ans)

Solution (Python):
n = int(input())
print((n*(n+1))//2)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())
sum = 0

for i in range(N + 1):
    sum += i

print(sum)

Solution (Python):
N = int(input())
print((N*(N+1))//2)

Solution (Python):
a=int(input())
ans=0
for i in range(1,a+1):
  ans+=i
print(ans)

Solution (Python):
a = int(input())
b=0
for i in range(0,a+1):
  b += i
print(b)

Solution (Python):
N = int(input())

print(sum(range(1, N + 1)))

Solution (Python):
n = int(input())
print(n*(n + 1)//2)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
def a(s):
  if s == 1:
    return s
  return s + a(s-1) 

print(a(int(input())))

Solution (Python):
N = int(input())

print(N * (N + 1) // 2)

Solution (Python):
n = int(input())
print(n*(n + 1) // 2)

Solution (Python):
n = int(input())
ans = 0

for i in range(n + 1):
    ans += i

print(ans)

Solution (Python):
x=int(input())
print(x*(x+1)//2)

Solution (Python):
num = int(input())
candy_num = 0

for i in range(1,num+1):
  candy_num += i

print(candy_num)

Solution (Python):
si = lambda: input()
ni = lambda: int(input())
nm = lambda: map(int, input().split())
nl = lambda: list(map(int, input().split()))
n = ni()
print(int((n*(n+1))/2))

Solution (Python):
from sys import stdin

n = int(stdin.readline().rstrip())

print(n*(n+1)//2)

Solution (Python):
N=int(input())
ans=N*(N+1)//2
print(ans)

Solution (Python):
n = int(input())

sum = 0
for i in range(n):
    sum += i+1

print(sum)

Solution (Python):

N=int(input())
S=0
for i in range(1,N+1):
    S=S+i
print(S)

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())

print(sum(range(N+1)))

Solution (Python):
n = int(input())
if n % 2 == 0:
  print(int((n+1)*n/2))
else:
  print(int((n+1)*(n-1)/2+(n+1)/2))

Solution (Python):
n = int(input())
print(int((n+1)*n/2))

Solution (Python):
x=int(input())
print(sum(range(x+1)))

Solution (Python):
print(sum(range(int(input())+1)))

Solution (Python):
n = int(input())
ans = 0
for i in range(1, n+1):
    ans += i
print(ans)

Solution (Python):
n = int(input())

number=0
for i in range(1,n+1):
    number +=i

print(number)

Solution (Python):
S=int(input())
ans=0
for i in range(1,S+1):
  ans+=i
print(ans)

Solution (Python):
a = int(input())
print(int((a * (a + 1)) / 2))

Solution (Python):
N = int(raw_input())
print sum(range(N + 1))

Solution (Python):
N = int(input())

candy = 0
for num in range(N+1):
    candy += num

print(candy)

Solution (Python):
n=int(input())
r=0
for i in range(n):
  r=r+i+1

print(r)

Solution (Python):
N = int(input())
print(N * (N + 1) // 2)

Solution (Python):
n = int(input())
print(sum([i for i in range(1, n+1)]))

Solution (Python):
N=int(input())
print((1+N)*N//2)

Solution (Python):
n = int(input())
count = 0
for i in range(n):
    count += i+1
print(count)

Solution (Python):
n = int(input())
print((n * (n+1)) // 2)

Solution (Python):
import math

n = int(input())
print(int(n * (n + 1) / 2))

Solution (Python):
n=int(input());print(n*(n+1)//2)

Solution (Python):
n = int(input())
print(((n)*(n+1))//2)

Solution (Python):
N = int(input())
print(sum(list(range(1,N+1))))

Solution (Python):
N = int(input())
camdy_for_pair =  (1 + N)
num_of_pairs, amari = divmod((N),2)

if amari == 0:
    nesseary_candy = num_of_pairs * camdy_for_pair
else :
    nesseary_candy = num_of_pairs * camdy_for_pair + num_of_pairs + 1
    
print(nesseary_candy)

Solution (Python):
N = int(input())
ans = sum(i for i in range(1,N+1))
print(ans)

Solution (Python):
n = int(raw_input())
out = 0

for i in range(1, n+1):
  out += i
print(out)

Solution (Python):
n = int(input())

a = 0
for n in range(1, n+1):
    a = n + a
print(a)

Solution (Python):
n = int(input())
print(n*(n+1) //2)

Solution (Python):
N = int(input())

Answer = N * (N + 1) // 2
print(Answer)

Solution (Python):
N = int(input())
t = 0

for i in range(N):
	t += i + 1 

print(t)

Solution (Python):
n = int(input())
print(n*(n + 1)//2)

Solution (Python):
n = int(input())
s = n*(n+1)/2
print (int(s))

Solution (Python):


N=int(input())

print(int((N+1)*N/2))

Solution (Python):
n = int(input())
ans = 0
for i in range(n):
    ans += n
    n -= 1
print(ans)

Solution (Python):
number=int(input())

print(int(number*(number+1)/2))

Solution (Python):


N = int(input())

sum = 0

for i in range(N+1):
	sum += i

print(sum)

Solution (Python):
N = int(input())

print(int(N*(N+1)/2))

Solution (Python):

import sys, math, itertools, heapq, collections, bisect, fractions
input = lambda: sys.stdin.buffer.readline().rstrip().decode('utf-8')
sys.setrecursionlimit(10**8)
inf = float('inf')
ans = count = 0

n=int(input())
print(sum(range(n+1)))

Solution (Python):
N = int(input())
print(int(N*(N+1)/2))

Solution (Python):
N = int(input())

X = 0

for i in range(N + 1):
  X = X + i

print(X)

Solution (Python):
N = int(input())

X = []

for i in range(N):
  Y = i + 1
  X.append(Y)

print(sum(X))

Solution (Python):
N =int(input())
c = 0
for i in range(N+1):
    c += i
print(c)

Solution (Python):
n=int(input())
print(int((n*(1+n)/2)))

Solution (Python):
N=int(input())
sum=0
for i in range(N):
    sum+=i+1
print(sum)

Solution (Python):
N = int(input())
print(N*(N+1)//2)

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(readline())

t = 0
for i in range(1, N+1):
  t += i
  
print(t)

Solution (Python):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(readline())

t = 0
for i in range(1, N+1):
  t += i
  
print(t)

Solution (Python):
def main():
    N = int(input())
    
    print(N*(N+1)//2)

if __name__ == '__main__':
    main()

Solution (Python):
def main():
    N = int(input())
    ans = 0

    for i in range(N):
        ans += i + 1
    
    print(ans)

if __name__ == '__main__':
    main()

Solution (Python):
N = int(input())
print(N * (N+1) // 2)

Solution (Python):
N = int(input())
print(N*(N+1)//2)

Solution (Python):
m = int(input())
result = 0
for i in range(1, m+1):
    result += i
print(result)

Solution (Python):
n = int(input())
result = 0
for i in range(1, n+1):
    result += i
print(result)

Solution (Python):
n=int(input())
print((1+n)*(n//2) + (n%2)*((1+n)//2))

Solution (Python):
n=int(input())
a=0
for i in range(n+1):
  a+=i
print(a)

Solution (Python):
m=0
n=int(input()) 
for i in range(n):
    m += i+1
print(m)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
N=int(input()) 
print(int((N+1)*N/2))

Solution (Python):
N=int(input()) 
ans = 0
for i in range(N+1):
    ans += i
print(ans)

Solution (Python):
N = int(input())
r=0
for i in range(N):
  r +=i+1
print(r)

Solution (Python):
N = int(input())
print( int(N*(N+1)/2))

Solution (Python):
n = int(input())
ans = int(n * (n + 1) /2)
print(ans)

Solution (Python):
n = int(input())
ans = n * (n+1) // 2
print(ans)

Solution (Python):
n = int(input())

print(n * (n+1) // 2)

Solution (Python):
i = int(input())
print(int(i*(i + 1) /2))

Solution (Python):
import numpy as np
n = int(input())

list = np.array(range(n+1))

print(sum(list))

Solution (Python):
N = int(input())
result = int((N + 1) * N / 2)
print(result)

Solution (Python):
def examA():
    N = I()
    sum = 0
    for i in range(N):
        sum +=(i+1)
    ans = sum
    print(sum)



import sys
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))
def LS(): return sys.stdin.readline().split()
def S(): return sys.stdin.readline().strip()
mod = 10**9 + 7
inf = float('inf')

examA()

Solution (Python):
num = int(input())

ans = 0
for i in range(num+1):
  ans += i
print(ans)

Solution (Python):
n = int(input())

k = (n + 1) * n / 2

print(int(k))

Solution (Python):
n = int(input())

ans = n * (n + 1) // 2

print(ans)

Solution (Python):



N = int(input())

sum = 0
for i in range(1, N+1) :
  sum += i

print(sum)

Solution (Python):

import sys
input = sys.stdin.readline


N = int(input())
print(N*(N+1)//2)

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n=int(input())
sum=0

for i in range(n):
  sum+=(i+1)
print(sum)

Solution (Python):
N = int(input())
j=0
k=1
for i in range(N):
  j = j + k
  k = k + 1
print(j)

Solution (Python):
N=int(input())
print(round((N+1)*N/2))

Solution (Python):
N = int(input())
print((N * (N + 1)) // 2)

Solution (Python):
n = int(input())
ans = 0
for i in range(1, n+1):
    ans += i
print(ans)

Solution (Python):
f=lambda x:x*(x+1)//2
print(f(int(input())))

Solution (Python):
N = int(input())
ans = 0

for i in range(N):
  ans += i+1

print(ans)

Solution (Python):
n=int(input())
print(int(n*(n+1)/2))

Solution (Python):


num = int(input())
total = 0

for i in range(num):
  total = total + i + 1
  
print(total)

Solution (Python):
N = int(input())
S = N * (N+1) / 2
print(int(S))

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())

print(n*(n+1)//2)

Solution (Python):


n = int(input())

a=0
for i in range(1,n+1):
	a = a + i
    
print(a)

Solution (Python):


n = int(input())

print(n*(1+n)//2)

Solution (Python):
N=int(input())

def souwa(n):
    if n==1:
        return 1
    else:
        return n+souwa(n-1)

x=souwa(N)
print(x)

Solution (Python):
N = int(input())

sum = 0
for i in range(1, N+1):
    sum += i

print(sum)

Solution (Python):
N = int(input())
print((N*(N+1))//2)

Solution (Python):
N = int(input())
print(int(N*(N+1)/2))

Solution (Python):
n = int(input())

print(round(n*(n+1)/2))

Solution (Python):
N = int(input())
S = N*(N+1)//2
print(S)

Solution (Python):
n = int(input())
print((n*(n+1))//2)

Solution (Python):

N = int(input())

sum = 0
for i in range(N+1):
  sum += i

print(sum)

Solution (Python):
N = int(input())
print(int(N * (N + 1) / 2))

Solution (Python):
N = int(input())

result = 0
for i in range(1,N+1):
  result += i

print(result)

Solution (Python):
n=int(input())
print((int)((n*(n+1))/2))

Solution (Python):
N = int(input())
a = 0
for n in range(N):
  n = n + 1
  a = a + n
print(a)

Solution (Python):
N = int(input())
candy_sum = int((1+N)*N/2)
print(candy_sum)

Solution (Python):
n =int(input())
print((n+1) * n //2)

Solution (Python):
N = int(input())
ans = 0
for i in range(N+1):
  ans += i
print(ans)

Solution (Python):
n=int(input())
print(n*(1+n)//2)

Solution (Python):
N=int(input())
count=0
for i in range(1,N+1):
    count+=i
print(count)

Solution (Python):
N=int(input())
S=0
for i in range(N):
  S+=i+1
print(S)

Solution (Python):
n = int(input());
ans = 0;

for i in range(n):
    ans += i + 1;
    
print(ans);

Solution (Python):
n = int(input())
print((n*(n+1))//2)

Solution (Python):
N = int(input())

print(int(N*(N+1)/2))

Solution (Python):
ary = [i+1 for i in range(int(input()))]
print(sum(ary))

Solution (Python):
n = int(input())

ans = int((1 + n) * n / 2)

print(ans)

Solution (Python):
N = int(input())
if N == 1:
    print(1)
elif N%2 != 0:
    print((1+N)*(N//2)+(N-N//2))
else:
    print((1+N)*(N//2))

Solution (Python):
n=int(input())
print(n*(n+1)//2)

Solution (Python):
n = int(input())
print(int(n*(n+1)/2))

Solution (Python):
n = int(input())
l = list(range(1, (n + 1)))
print(sum(l))

Solution (Python):
N = int(input())
S = 0

for i in range(1,N+1):
    S += i
print(S)

Solution (Python):
N = int(input())
print(sum([i for i in range(1, N+1)]))

Solution (Python):
n = int(input())
print(n*(n+1)//2)

Solution (Python):
N = int(input())
print(int(0.5*N*(N+1)))

Solution (Python):
n = int(input())
ans = 0
counter = 1
for i in range(n):
    ans += counter
    counter += 1
print(ans)

Solution (Python):
N=int(input());print(sum(range(1,N+1)))

Solution (Python):
a=int(input())
print(int(a*(a+1)/2))

Solution (Python):
N = int(input())
print( N*(N+1)//2)