#include <stdio.h> int main() { int x1, y1, x2, y2; scanf("%d", &x1); scanf("%d", &y1); scanf("%d", &x2); scanf("%d", &y2); // 计算两个时刻的总分钟数 int total_a = x1 * 60 + y1; int total_b = x2 * 60 + y2; // 计算差值（考虑跨天情况） int diff = total_b - total_a; if (diff < 0) { diff += 24 * 60; // 加上一天的分钟数 } printf("%d\n", diff); return 0; }