The law of 1 * 2 * 3 * 4 * 5 * 6 * ····· n

The law of 1 * 2 * 3 * 4 * 5 * 6 * ····· n

There are two zeros at the end of 1 * 2 * 3 * 4 * 5 * 6 *. * 10. Similarly, there are two 0101 *. 110 at the end of 11 *. * 20
So: 1 * 2 * 3 * 4 * 5 * 6 ········ * 100 has 19 zeros (26-19) / 2 = 3 more than 1 at the end
So there are 27 zeros at the end of 140, so it should be multiplied by 139