The possibility of choosing a flat code depends on your mathematical calculation and personal preference, but here are some tips for choosing a flat code: 1. Study historical data: Look at previous lottery data to see which numbers are often selected. 2. Choose an unpopular number: choose a number that is not often chosen, so that even if you win the prize, you have a greater chance of getting more bonuses. 3. Choose popular numbers: Choose numbers that are often selected, because these numbers have a higher probability of winning. 4. Choose serial numbers: choose adjacent numbers, because in historical data, serial numbers are more likely to win prizes. 5. Choose a number with a large span: the span refers to the difference between the largest number and the smallest number among the five selected numbers. Choose a number with a large span, so that even if the probability of winning is low, the winning prize will be higher. The above are some tips for choosing a flat code, but the final choice of which number depends on your own preferences and mathematical calculations.