Python - NameError: name 'sumpar' is not defined

lista = list(map(int, input().strip().split(' ')))

sum=0

for i in range(len(lista)):

    if len(lista) == 1:

        print("PARES")

    elif i % 2 == 0:

        sumpar = sum+lista[i]

    elif i % 2 != 0:

        sumimpar = sum+lista[i]

if sumpar > sumimpar:

    print ("PARES")

elif sumpar < sumimpar:

    print("IMPARES")

elif sumpar == sumimpar:

    print("IGUALES")

lista = list(map(int, input().strip().split(' ')))

sumpar = sumimpar= suma = 0

for i in range(len(lista)):

    if len(lista) == 1:

        print("PARES")

    elif i % 2 == 0:

        sumpar = suma+lista[i]

    elif i % 2 != 0:

        sumimpar = suma+lista[i]

if sumpar > sumimpar:

    print ("PARES")

elif sumpar < sumimpar:

    print("IMPARES")

elif sumpar == sumimpar:

    print("IGUALES")