Final — B: The Vault Clock

**Description:** A vault door shows a 4-digit display (0000..9999). Each second you may press one of two buttons: +1 or -1 on the LAST digit (wrapping: 9+1=0, 0-1=9). Given the current display and the target display, print the minimum number of seconds. **Input:** Line 1: t (1 <= t <= 100000). Next t lines: two 4-digit strings cur and target. **Output:** t lines: the minimum presses for each case. **Example:** 1 / 1234 1230 -> 4 (press -1 four times on the last digit).