#include <stdio.h>

int main() {
	int kg;
	double st, lt, Q;

	printf("Enter weight in kilograms: ");
	scanf_s("%d", &kg);

	printf("Enter water temperature:");
	scanf_s("%lf", &st);

	printf("Enter water finnal temperature:");
	scanf_s("%lf", &lt);

	Q = kg * (lt - st) * 4184;

	printf("水从初始温度加热到最终温度需要的能量是：%.2lf焦耳", Q);

	return 0;
}