diff --git a/3.c b/3.c
new file mode 100644
index 0000000..1311ed7
--- /dev/null
+++ b/3.c
@@ -0,0 +1,67 @@
+#include <stdio.h>
+
+struct Data
+{
+	int ID;
+	float score1;
+	float score2;
+	float score3;
+} stu[1001];
+int stl = 0, sortstl;
+
+float total(struct Data* a) {
+	return a->score1 + a->score2 + a->score3;
+}
+
+void swap(struct Data* a, struct Data* b) {
+	struct Data t = *a;
+	*a = *b;
+	*b = t;
+}
+
+void input1() {
+	scanf("%d", &stu[stl].ID);
+	scanf("%f", &stu[stl].score1);
+	scanf("%f", &stu[stl].score2);
+	scanf("%f", &stu[stl].score3);
+	stl++;
+}
+
+
+void Input() {
+	printf("Please input info of three students:\n");
+	input1();input1();input1();
+	if (total(&stu[stl-3]) < total(&stu[stl-2])) swap(&stu[stl-3], &stu[stl-2]);
+	if (total(&stu[stl-2]) < total(&stu[stl-1])) swap(&stu[stl-2], &stu[stl-1]);
+	if (total(&stu[stl-3]) < total(&stu[stl-2])) swap(&stu[stl-3], &stu[stl-2]);
+	printf("%d,%.1f,%.1f\n", stu[stl-3].ID, total(&stu[stl-3]), total(&stu[stl-3])/3.0f);
+	printf("%d,%.1f,%.1f\n", stu[stl-2].ID, total(&stu[stl-2]), total(&stu[stl-2])/3.0f);
+	printf("%d,%.1f,%.1f\n", stu[stl-1].ID, total(&stu[stl-1]), total(&stu[stl-1])/3.0f);
+}
+
+int main() {
+	printf("                              1.Input\n");
+	printf("                              2.Output\n");
+	printf("                              3.Order\n");
+	printf("                              4.Quit\n");
+	char t;
+	scanf("%c", &t);
+	switch(t) {
+		case 'i':
+		printf("You are trying to Input info\n");
+		Input();
+		break;
+		case 'o':
+		printf("You are trying to Output info\n");
+		break;
+		case 'm':
+		printf("You are trying to Make things ordered\n");
+		break;
+		case 'q':
+		printf("You are trying to Quit\n");
+		break;
+		default:
+		printf("Wrong input\n");
+		break;
+	}
+}
\ No newline at end of file