21488:316:68+(3600•409-3805•0):818:100•1

Result: 19

Reason (interpreting the operators):

• Colon (:) = division, left-to-right.
• Dot (•) = multiplication.

First part: 21488:316:68 = (21488/316)/68 = 68/68 = 1.

Second part: (3600•409 - 3805•0):818:100•1

• 3805•0 = 0, so 3600•409 = 1,472,400.
• Then 1,472,400:818:100•1 = ((1,472,400/818)/100)*1 = (1,800/100)*1 = 18.

Total: 1 + 18 = 19.