diff --git a/main.c b/4545.c
similarity index 61%
rename from main.c
rename to 4545.c
index a2fa339..832d968 100644
--- a/main.c
+++ b/4545.c
@@ -9,13 +9,16 @@ int sjfu()
 int main()
 {
     char a[]={'+','-'};
-    int b,c,d,t,i,j,f;
+    int b,c,d,t,i,j,f,su=0;
     int daan,fenshu=0;
+    printf("--------------------------------------------------------------\n");
+    printf("\n\t请输入以下10个计算题的答案\n\t（别着急，每个题有三次输入的机会哦）\n\n");
+    printf("--------------------------------------------------------------\n\n");
     for(i=0;i<10;i++)
     {
         srand( (unsigned)time( NULL ));
-        b=rand()%50;
-        c=rand()%50;
+        b=rand()%51;
+        c=rand()%51;
         d=sjfu();
         if(b<c)
         {   t=b;b=c;c=t;}
@@ -28,8 +31,9 @@ int main()
 
         if(daan>50)
         {   i-=1;continue;}                                    //判断算式是否符合要求
-
-        printf("\t%d%c%d=?\n",b,a[d],c);                           //形成随机算式，并输出
+        su=i;
+        printf("第%d题\n",su+1);
+        printf("\t%d%c%d=?\n\n",b,a[d],c);                     //输出算式题
 
 
         for(j=0;j<3;j++)
@@ -38,17 +42,17 @@ int main()
         if(f==daan)
             break;
         else
-            printf("答案不对哦，再想想看~\n");
-        }                                                      //用户输入答案
+            printf("答案不对哦，再想想看\n");
+        }                                                      //用户输入答案（三次机会）
 
         switch(j)
         {
             case 0:{fenshu+=10;break;}
             case 1:{fenshu+=7;break;}
             case 2:{fenshu+=5;break;}
-            case 3:{fenshu+=0;printf("%d\n",daan);break;}
-        }                                                      //判断得分或输出该算式答案
-
+            case 3:{fenshu+=0;printf("\n\t很可惜\n\t正确答案是 %d\n",daan);break;}
+        }                                                      //判断输出该算式答案，并计算得分
+        printf("\n--------------------------------------------------------------\n\n");
     }
     if(fenshu>=90)
         printf("SMART\n");
@@ -59,6 +63,6 @@ int main()
     else if(fenshu<70&&fenshu>=60)
         printf("PASS\n");
     else
-        printf("TRY AGAIN\n");                                 //判断等级
+        printf("TRY AGAIN\n");   //判断等级
     return 0;
 }