3 bits sum

sum of 3 bits, code or example please

Which three?

0+0+0=0
0+0+1=1
0+1+1=2
1+1+1=3

Tsk, Tsk.
0+1+1=10
1+1+1=11

Pete

1+1+1=11

1+1+1=0b11

Tsk tsk

not enough requirements. How much bits is the input / answer max?

Mind you another 3 bits sum could be 101₂ + 011₂ = 000₂

"There are 10 types of people in the World. Those that understand binary and those that don't"