I want to condense a list of from to data?

I am new to programming and have data involving codes assigned to distances in the form of

From To Code 0 5 A 5 10 A 10 15 A 15 20 B 20 25 B 25 30 A 30 35 A 35 40 A 40 45 C 45 50 C 50 55 C 55 60 B 60 65 B 65 70 B

I want to condense this list to a list like this

From To Code 0 15 A 15 25 B 25 40 A 40 55 C 55 70 B

I am wondering if this could be done by sed or awk.