C$++$ provides several data types: char: $1$ byte, largest value: $127$ short: $2$ bytes, largest value: $32,767$ int: $4$ bytes, largest value: $2,147,483,647$ long long: $8$ bytes, largest value: $9,223,372,036,854,775,807$Those are puny numbers if we want to calculate Fibonacci$(12345)...$We need to create a new class the BigInt class.We will use overloadedC$++$ provides several data types: char: $1$ byte, largest value: $127$ short: $2$ bytes, largest value: $32,767$ int: $4$ bytes, largest value: $2,147,$