贷款分期偿还

def solve(____):
    pmt = principal * rate * (____ + rate) ** nper / ((____ + rate) ** nper - ____)
    total_payment = pmt * nper
    total_interest = total_payment - principal
    return {"____": principal, "____": rate, "____": nper, "____": round(____), "____": round(____)}