diff --git a/a6.c b/a6.c
new file mode 100644
index 0000000..af62cfd
--- /dev/null
+++ b/a6.c
@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <string.h>
+struct stu {
+    char num[6];
+    char class[3];
+    char name[6];
+    float grade1;
+    float grade2;
+    float grade3;
+    float grade;
+}s[10],ss;
+int main()
+{
+	strcpy(s[0].num,"10001");strcpy(s[0].class,"11");strcpy(s[0].name,"Zhang");s[0].grade1=99.5;s[0].grade2=88.5;s[0].grade3=89.5;s[0].grade=s[0].grade1+s[0].grade2+s[0].grade3;
+	strcpy(s[1].num,"10002");strcpy(s[1].class,"12");strcpy(s[1].name,"Yang");s[1].grade1=77.9;s[1].grade2=56.5;s[1].grade3=87.5;s[1].grade=s[1].grade1+s[1].grade2+s[1].grade3;
+	strcpy(s[2].num,"10003");strcpy(s[2].class,"11");strcpy(s[2].name,"Liang");s[2].grade1=92.5;s[2].grade2=99.0;s[2].grade3=60.5;s[2].grade=s[2].grade1+s[2].grade2+s[2].grade3;
+	scanf("%s%s%s%f%f%f",s[3].num,s[3].class,s[3].name,&s[3].grade1,&s[3].grade2,&s[3].grade3);
+	s[3].grade=s[3].grade1+s[3].grade2+s[3].grade3;
+	for(int i=0;i<3;i++)
+	{
+		if(strcmp(s[i].num,s[3].num)==0)
+		{
+			s[i]=s[3];
+		}
+	}
+	for(int i=0;i<2;i++)
+	{
+	    for(int j=i+1;j<3;j++)
+	    {
+	    	if(strcmp(s[i].class,s[j].class)>0)
+	    	{
+	    		ss=s[i];
+	    		s[i]=s[j];
+	    		s[j]=ss;
+			}		
+		}
+	}
+	for(int i=0;strcmp(s[i].class,s[0].class)==0;i++)
+	    {
+	    	for(int j=i+1;strcmp(s[j].class,s[0].class)==0;j++)
+	    	{
+	    		if(s[i].grade<s[j].grade)
+	    		{
+	    			ss=s[i];
+	    			s[i]=s[j];
+	    			s[j]=ss;
+				}
+	    		
+			}
+		}
+	for(int i=1;strcmp(s[i].class,s[0].class)==0;i++)
+	{
+	    strcpy(s[i].class,"  ");
+	}
+	for(int i=0;i<3;i++)
+	{
+	     printf("%s %s %s %.1f %.1f %.1f",s[i].class,s[i].num,s[i].name,s[i].grade1,s[i].grade2,s[i].grade3);
+	     if(strcmp(s[3].num,s[i].num)==0)
+	     printf(" modified\n");
+	     else
+	     printf("\n");
+    }
+	return 0;
+}
\ No newline at end of file