Your loop is written that it will stop when all a, b and c is greater than 70.
If you want to stop when at least one of the parameter is greater than 70, changee || to && in while condition.
i'm using turbo c
Stop using it. .h versions of headers became obsolete in 1998. You are 15 years behind progress. Also it has numerous bugs, lack support of numerous features. You might find that skill you will acquire using turbo c is useless with modern C++.