634 B | 634 chars
import sys
from math import sqrt, pi, sin, factorial
inp = lambda : sys.stdin.readline()[:-1]
mii = lambda x = " ": [*map(int,inp().split(x))]
mfi = lambda x = " ": [*map(float,inp().split(x))]
ii = lambda : int(inp())
n = ii()
l = mii()
idx = []
a_idx = []
b_idx = []
for i in range(n):
if i % 2 == l[i] % 2:
idx.append(i + 1)
if i % 2:
a_idx.append(i + 1)
else:
b_idx.append(i + 1)
if len(idx) == 2:
if len(a_idx) == len(b_idx):
print(*idx)
else:
print(-1, -1)
elif len(idx) > 2 or len(idx) == 1:
print(-1, -1)
elif len(idx) == 0:
if n > 2:
print(1, 3)
else:
print(-1, -1)