3²⁵ + 2²⁷ is divisible by

First, I apply 'Unit Digit Analysis' [1, 6]. The cycle of 3 is {3, 9, 7, 1}, so $3^{25} = 3^{4\times6+1}$ ends in 3. The cycle of 2 is {2, 4, 8, 6}, so $2^{27} = 2^{4\times6+3}$ ends in 8. The sum $3+8=11$ ends in