diff --git a/26_Seminar13/27_Microcontrollers/2_1_bits.c b/26_Seminar13/27_Microcontrollers/2_1_bits.c
index 0dfc771..841fef3 100644
--- a/26_Seminar13/27_Microcontrollers/2_1_bits.c
+++ b/26_Seminar13/27_Microcontrollers/2_1_bits.c
@@ -35,7 +35,7 @@ int main()
     uint32_t a=4096;
     uint32_t b=0x7fffffff;
     uint32_t c=1<<(32-9);
-    uint32_t d=0xffff;
+    uint32_t d=1<<(32-10);
     int status = 0;
     //~ scanf("%x%x%x%x", &a, &b, &c, &d); //a=4095, b=2000, c=4095, d=0xffff
     set_all_bits(&a);
@@ -50,9 +50,8 @@ int main()
     printf("reset_some_bits %d %#X %f\n",status, b, var);
     status = reset_some_bits( &var, ~c );
     printf("reset_some_bits %d %#X %f\n",status, c, var);
-    set_all_bits(&var);
-    status = reset_some_bits(&var, d);
-    printf("reset_some_bits %d %#X %f\n",status, a, var);
+    status = reset_some_bits(&var, ~d);
+    printf("reset_some_bits %d %#X %f\n",status, d, var);
 
     return 0;
 }
diff --git a/26_Seminar13/27_Microcontrollers/2_1_bits.exe b/26_Seminar13/27_Microcontrollers/2_1_bits.exe
deleted file mode 100644
index f8eec35..0000000
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diff --git a/26_Seminar13/27_Microcontrollers/2_1_bits.o b/26_Seminar13/27_Microcontrollers/2_1_bits.o
deleted file mode 100644
index 0aad0d1..0000000
Binary files a/26_Seminar13/27_Microcontrollers/2_1_bits.o and /dev/null differ