def info(res,n):
    print(f"trappen({n}) = trappen({n-1}) + trappen({n-2}) = {res}")

def trappen(n):
    if n < 2:
        return 1
    else:
        res = trappen(n - 1) + trappen(n - 2)
        info(res, n) 
        return res
    
trappen(5)