Poke Dice

There are $N$ pokemon in a class, each pokemon is given 2 fair dice. One of the dice contains : 2, 7, 12, 17, 22 & 27 and the other dice contains : 3, 8, 13, 18, 23 & 28. The pokemon are asked to throw both the dice $M$-times and sum up whatever comes each time on both the dice and add all the outcomes. You ask each pokemon the sum of all the outcomes but strangely some of them are lying.