Design a system that gets two 4-bit numbers X_{3}X_{2}X_{1}X_{0} , Y_{3}Y_{2}Y_{1}Y_{0} in the range of 0-9 and the output of the system is the addition result between these two numbers (Z_{4}Z_{3}Z_{2}Z_{1}Z_{0}) while the MSB, Z_{4 }is the tens and Z_{3}Z_{2}Z_{1}Z_{0} are the units digits.

**For example:** X_{3}X_{2}X_{1}X_{0 }= 8 (1000) , Y_{3}Y_{2}Y_{1}Y_{0 }= 5 (0101) , Z_{4}Z_{3}Z_{2}Z_{1}Z_{0 } = 13 (1-0011)

X_{3}X_{2}X_{1}X_{0 }= 9 (1001) , Y_{3}Y_{2}Y_{1}Y_{0 }= 1 (0001) , Z_{4}Z_{3}Z_{2}Z_{1}Z_{0 } = 10 (1-0000)

X_{3}X_{2}X_{1}X_{0 }= 4 (0100) , Y_{3}Y_{2}Y_{1}Y_{0 }= 3 (0011) , Z_{4}Z_{3}Z_{2}Z_{1}Z_{0 } = 7 (0-0111)

In order to design the system you have two 4-bit adders, OR and AND gates as many as you like and constants (‘0’ and ‘1’).