diff --git a/program 4.c b/program 4.c
new file mode 100644
index 0000000..a389b89
--- /dev/null
+++ b/program 4.c	
@@ -0,0 +1,55 @@
+#include<stdio.h>
+struct stu
+{
+	int num,c,x;
+	float m,p,e,s;
+};
+
+struct stu stu[4]={{10001,11,0,99.5,88.5,89.5,277.5},
+						{10002,12,0,77.9,56.5,87.5,221.9},
+						{10003,11,0,92.5,99.0,60.5,252},{}};
+
+void min(struct stu *stu,int n)
+{
+	int i,j;
+	struct stu t;
+	for(i=0;i<n;i++)
+	{
+		for(j=0;j<n-i-1;j++)
+		{
+			if(((stu+j)->c>(stu+j+1)->c)||((stu+j)->c==(stu+j+1)->c)&&((stu+j)->s<(stu+j+1)->s))
+			{
+				t = *(stu+j);
+				*(stu+j) = *(stu+j+1);
+				*(stu+j+1) = t;
+			} 
+		}
+	}
+	return;
+}
+
+int main()
+{
+	scanf("%d",&stu[3].num);
+	scanf("%d",&stu[3].c);
+	scanf("%f",&stu[3].m);
+	scanf("%f",&stu[3].p);
+	scanf("%f",&stu[3].e);
+	stu[3].x=1;
+	stu[3].s=stu[3].m+stu[3].p+stu[3].e;
+	int z=1,i,n=4;
+	for(i=0;i<3;i++) if(stu[i].num==stu[3].num) z=0;
+	if(z==0) n=3;
+	for(i=0;i<3;i++){
+	if(stu[3].num==stu[i].num){
+	printf("%d existed\n",stu[i].num);
+	return 0;}}
+	min(stu,n);
+	for(i=0;i<n;i++)
+	{
+		printf("%d %d %.1f %.1f %.1f",stu[i].num,stu[i].c,stu[i].m,stu[i].p,stu[i].e);
+		if(stu[i].x) printf(" inserted");
+		printf("\n"); 
+	}
+	return 0;
+}