import math
def sum1(n):
    suma=0
    for i in range(1,n+1):
        suma+=i
    return suma
def sum2(n):
    suma=0
    for i in range(1,n+1):
        suma+=2*i-1
    return suma
def sum3(n):
    suma=0
    for i in range(1,n+1):
        suma+=1/(i**2+i)
    return suma
def sum4(n,x):
    suma=0
    for i in range(1,n+1):
        suma+=x**(1/(i+1))
    return suma
def sum5(n):
    suma=0
    for i in range(0,n):
        suma+=(-2)**i
    return suma
def sum6(n):
    suma=0
    for i in range(1,n+1):
        suma+=1/i**3
    return suma
def sum7(n):
    suma=0
    for i in range(1,n+1):
        suma+=(-1)**i
    return suma
def ilo1(n):
    ilo=0
    for i in range(1,n+1):
        ilo*=i-1
    return ilo
def ilo2(n):
    ilo=0
    for i in range(1,n+1):
        ilo=i**(-i)
    return ilo
def ilo3(n):
    ilo=0
    for i in range(1,n+1):
        ilo=1/i**3
        return ilo

print(sum1(3))
print(sum2(4))
print(round(sum3(5),2))
print(sum4(1,9))
print(sum5(5))
print(round(sum6(6),2))
print(sum7(7))
print(ilo1(4))
print(ilo2(2))
print(ilo3(7))