The specific identification number consists of five symbols: S 1, S2, D 1, D2 and D3. The first two symbols must be one of 26 English letters, and the last three symbols must be 10 digits (0-9). Duplicate letters and numbers are allowed. )。 What is the total number of different identification codes?

This is a question of permutation and combination. The first two symbols are 26 letters with 26 choices, and the last three symbols are 10 digits with 10 choices.

It should be 26 * 26 *10 *10 *10 = 676000.