A recording medium recording a combine, a quantity calculation method, a quantity calculation system, a quantity calculation program, and a quantity calculation program, and a grain discharge quantity calculation method, a grain discharge quantity calculation system, a grain discharge quantity calculation program, and a grain discharge quantity calculation program are recorded. A recording medium, a fraudulent inflow detection system, a fraudulent inflow detection program, a recording medium recording the fraudulent inflow detection program, and a fraudulent inflow detection method, and a storage level detection system