Design a logic circuit that will decode a DTMF-like keypad. The keypad consists of 16 keys, numbered 0 to 9, *, #, A, B, C, and D. Underneath the keypad are four horizontal lines and four vertical lines. The horizontal lines are numbered 0 to 3, and the vertical lines are numbered 4 to 7. When a vertical line is pressed against a horizontal line, a digital pattern is provided. So, when line 0 and line 4 are pressed together, the pattern for 1 (0001) is displayed. When line 0 is pressed with line 4, the pattern for *A (1010) is displayed. And for *, lines 0 and 7 are pressed to give (1110). Thus, 1111 would be the #, meaning that lines 3 and 7 have been pressed.