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

Solution (Python):
import sys
import numpy as np
import random
from decimal import Decimal
import itertools
import re
import bisect
from collections import deque, Counter
from functools import lru_cache

sys.setrecursionlimit(10**9)
INF = 10**13
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def I(): return int(sys.stdin.buffer.readline())
def LS(): return sys.stdin.buffer.readline().rstrip().decode('utf-8').split()
def S(): return sys.stdin.buffer.readline().rstrip().decode('utf-8')
def IR(n): return [I() for i in range(n)]
def LIR(n): return [LI() for i in range(n)]
def SR(n): return [S() for i in range(n)]
def LSR(n): return [LS() for i in range(n)]
def SRL(n): return [list(S()) for i in range(n)]
def MSRL(n): return [[int(j) for j in list(S())] for i in range(n)]
def SERIES(n): return np.fromstring(sys.stdin.buffer.read(), dtype=np.int32, sep=' ')
def GRID(h,w): return np.fromstring(sys.stdin.buffer.read(), dtype=np.int32, sep=' ').reshape(h,-1)[:,:w]
def GRIDfromString(h,w): return np.frombuffer(sys.stdin.buffer.read(), 'S1').reshape(h,-1)[:,:w]
MOD = 1000000007

def main():
	n = I()
	print(n*(n+1)//2)


if __name__ == '__main__':
    main()

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

Solution (Python):
'''     
        
        
        

import sys
import math


def get_ints(): return map(int, input().strip().split())
def get_list(): return list(get_ints())

def printspx(*args): return print(*args, end="")
def printsp(*args): return print(*args, end=" ")
def printchk(*args): return print(*args, end=" \ ")

MODPRIME = int(1e9+7); BABYMODPR = 998244353;

ONLINE_JUDGE = 1
if not ONLINE_JUDGE:
    sys.stdin  = open("input.txt","r")
    sys.stdout = open("output.txt","w")
    sys.stderr = open("output.txt","w")


n = int(input())
print((n*(n+1))//2)
'''
>>> COMMENT THE STDIN!! CHANGE ONLINE JUDGE !!
THE LOGIC AND APPROACH IS BY ME @luctivud ( UDIT GUPTA )
SOME PARTS OF THE CODE HAS BEEN TAKEN FROM WEBSITES LIKE::
(I Own the code if no link is provided here or I may have missed mentioning it)
DO NOT PLAGIARISE.
TESTCASES:
>>> COMMENT THE STDIN!! CHANGE ONLINE JUDGE !!
'''

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

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

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

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

print(ans)

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

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

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

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

for num in range(a):
    ans=ans+(num+1)

print(ans)

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

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

Solution (Python):
import os, sys, re, math

N = int(input())

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

print(ret)

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

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

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

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+1):
    n +=i
print(n)

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

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

sum = (1 + N)*N/2

print(sum)

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

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

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

print(candy)

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

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

Solution (Python):
import sys

def sum(num) : 
  return int((1 / 2) * num * (num + 1))


for line in sys.stdin : 
  num = int(line)
  

print(sum(num))

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


def solve(N: int):
    res = (1 + N) * (N / 2)
    print(int(res))



def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word

    tokens = iterate_tokens()
    N = int(next(tokens))  
    solve(N)


if __name__ == "__main__":
    main()

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())

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

print(S)

Solution (Python):


N = int(input())

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

Solution (Python):
children_str=input()

children=int(children_str)

candies=0

while children >= 1:
  candies=candies+children
  children=children-1
  
print(candies)

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

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

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

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

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

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

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

print(sum)

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

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

total = 0

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

print(total)

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

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

Solution (Python):
N = input()
N = int(N)
point = 0
while N > 0:
    point = point + N
    N = N - 1
print(point)

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

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

print(ans)

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

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

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

Solution (Python):

n = int(input())

count = 0
for i in range(0,n+1):
    count += int(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):
n = int(input())
print(int(n*(1+n)/2))

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

Solution (Python):


n = int(input())


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


print(ans)

Solution (Python):
from statistics import median


from fractions import gcd
from itertools import combinations 
from collections import deque
from collections import defaultdict
import bisect










import sys
sys.setrecursionlimit(10000000)
mod = 10**9 + 7

def readInts():
  return list(map(int,input().split()))
def main():
    n = int(input())
    print((n*(n+1))//2)

if __name__ == '__main__':
  main()

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

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

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

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

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

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

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

if __name__ == '__main__':
    main()

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

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

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

Solution (Python):
import sys
input = sys.stdin.readline

n = int(input())

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

Solution (Python):
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,copy,functools
import time,random

sys.setrecursionlimit(10**7)
inf = 10**20
eps = 1.0 / 10**10
mod = 10**9+7
mod2 = 998244353
dd = [(-1,0),(0,1),(1,0),(0,-1)]
ddn = [(-1,0),(-1,1),(0,1),(1,1),(1,0),(1,-1),(0,-1),(-1,-1)]

def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(): return [list(map(int, l.split())) for l in sys.stdin.readlines()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()
def pf(s): return print(s, flush=True)
def pe(s): return print(str(s), file=sys.stderr)
def JA(a, sep): return sep.join(map(str, a))
def JAA(a, s, t): return s.join(t.join(map(str, b)) for b in a)


def main():
    n = I()

    return n * (n+1) // 2;

print(main())

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):
a = int(input())
sum = 0

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

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

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

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

Solution (Python):
n = int(input())
k = 0
if 1 <= n <= 100:
  for i in range(n):
    k += i + 1
print(k)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

print(number)

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

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

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

Solution (Python):

n=int(input())

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Solution (Python):
def main():
    import sys
    
    n = int(sys.stdin.readline())
    
    print(int(n*(n+1)/2))
    
if __name__ == "__main__":
    main()

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

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

print(ans)

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

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

n = 0

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

print(n)

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

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

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

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

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

Solution (Python):
x = int(input())
count = 0
while x > 0:
    count += x
    x -= 1
print(count)

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

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

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

candies = 0
for child in range(1,n+1):
    candies += child

print(candies)

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

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

Solution (Python):

import sys
sys.setrecursionlimit(10**9)
INF=10**18
MOD=10**9+7
input=lambda: sys.stdin.readline().rstrip()
YesNo=lambda b: bool([print('Yes')] if b else print('No'))
YESNO=lambda b: bool([print('YES')] if b else print('NO'))
int1=lambda x:int(x)-1

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

if __name__ == '__main__':
    main()

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

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

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

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

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

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



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

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

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

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

Solution (Python):
"""
N = list(map(int,input().split()))
S = [str(input()) for _ in range(N)]
S = [list(map(int,list(input()))) for _ in range(h)] 
print(*S,sep="")
"""

import sys
sys.setrecursionlimit(10**6)
input = lambda: sys.stdin.readline().rstrip()

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

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

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

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

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):


import sys






















def main():
    mod = 1000000007                
    inf = float('inf')              
    
    sys.setrecursionlimit(10**6)    
    def input(): return sys.stdin.readline().rstrip()
    def ii():    return int(input())
    def mi():    return map(int, input().split())
    def mi_0():  return map(lambda x: int(x)-1, input().split())
    def lmi():   return list(map(int, input().split()))
    def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))
    def li():    return list(input())
    
    
    n = ii()
    print(n * (n+1) // 2)


if __name__ == "__main__":
    main()

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())
m =0

m = 0.5*n*(n+1)
print(int(m))

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

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

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

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

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

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

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

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

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

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())
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):
def cin():
	return map(int,input().split())

def cino(test=False):
    if not test:
        return int(input())
    else:
        return input()
def cina():
  return list(map(int,input().split()))

a = cino()
print((a*(a+1))//2)

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

Solution (Python):
import sys
import math
import bisect

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

if __name__ == "__main__":
    main()

Solution (Python):
import sys
import itertools
sys.setrecursionlimit(1000000000)
from heapq import heapify,heappop,heappush,heappushpop
import math
import collections
MOD = 10**9+7

n = int(input())
print(int((1/2)*(n)*(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())
result = N * (N + 1) // 2
print('{}'.format(result))

Solution (Python):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, tan, asin, acos, atan, radians, degrees, log2
from itertools import accumulate, permutations, combinations, combinations_with_replacement, product, groupby
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from fractions import gcd
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7
 
N = INT()
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())
total = 0
for i in range(1, N + 1):
    total += i
print(total)

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())

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

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

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

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

total = 0

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

print(total)

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

print(total)

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

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

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

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

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

i = 1
ans = 0
while i<=n:
    ans += i
    i+=1

print(ans)

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

if __name__ == '__main__':
    main()

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

Solution (Python):
n = int(input())
print((2 + 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):
x=[i for i in range(1,int(input())+1)]
print(sum(x))

Solution (Python):


N = int(input())

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

Solution (Python):

def ABC_43_A():
    N = int(input())

    sum=0

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

    print(sum)

if __name__ == '__main__':

    ABC_43_A()

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

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

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

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

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

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

print(C)

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

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

print(Count)

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

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

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

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

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

Solution (Python):

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


if '__main__' == __name__:
    resolve()

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

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

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

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

def dfs(n):
    if n==1:
        return 1
    
    ans = n + dfs(n-1)
    return ans
print(dfs(N))

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

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

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

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

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())

count = 0

num = 1

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

print(count)

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):

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

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

Solution (Python):
s=int(input())
n=0
while(s>0):
  n=n+s
  s=s-1
print(n)

Solution (Python):
s=int(input())
n=0
while(s>0):
  n=n+s
  s=s-1
print(n)

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

sum=0

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

print(sum)

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

print(ans)

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

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

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

Solution (Python):
import sys
import heapq, math
from itertools import zip_longest, permutations, combinations, combinations_with_replacement
from itertools import accumulate, dropwhile, takewhile, groupby
from functools import lru_cache
from copy import deepcopy

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

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

Solution (Python):
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**7)
from collections import Counter, deque
from collections import defaultdict
from itertools import combinations, permutations, accumulate, groupby, product
from bisect import bisect_left,bisect_right
from heapq import heapify, heappop, heappush
from math import floor, ceil
from operator import itemgetter
def I(): return int(input())
def MI(): return map(int, input().split())
def LI(): return list(map(int, input().split()))
def LI2(): return [int(input()) for i in range(n)]
def MXI(): return [[LI()]for i in range(n)]
inf = 10**17
mod = 10**9 + 7


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

Solution (Python):
n = int(input())
def func(n):
    if n==1:
        return 1
    return n + func(n-1)
print(func(n))

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

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

print(SUM)

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

Solution (Python):
n= int(input())
con=0
soma=0
while con <= n:
	soma+=con
	con+=1

print(soma)

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

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

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

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

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

Solution (Python):
number = int(input())
total = 0

for i in range(number+1):
 total += i

print(total)

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

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

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

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

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

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

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

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

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

Solution (Python):
import sys

input = sys.stdin.readline


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


if __name__ == "__main__":
    main()

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

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

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

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

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

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

total = 0

for n in range(1, num+1):
    total += n

print(total)

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


print(ans)

Solution (Python):
def main():
    import sys
    input = sys.stdin.readline
    sys.setrecursionlimit(10**7)
    from collections import Counter, deque
    
    from itertools import combinations, permutations, accumulate, groupby, product
    from bisect import bisect_left,bisect_right
    from heapq import heapify, heappop, heappush
    from math import floor, ceil
    

    
    

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

if __name__ == '__main__':
    main()

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

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

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

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())

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

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

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

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

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

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

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

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

P = 0

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

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

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

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

print(ans)

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

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

print(ans)

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

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

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

print(ans)