diff --git a/src/main/c/BasicMode.c b/src/main/c/BasicMode.c
index a9e60fc..a338063 100644
--- a/src/main/c/BasicMode.c
+++ b/src/main/c/BasicMode.c
@@ -71,6 +71,40 @@ int main() {
  do {
      printf("what do you want to do?(A for conversion from decimal base to binary base ,B for conversion from binary base to decimal base ,C for Operation in binary base, Q for stop):");
      scanf(" %c", &auswahl1);
+      switch (auswahl1) {
+ case 'A':
+ case 'a':
+     printf("Enter a decimal number: ");
+     scanf("%lld", &dec);
+     bin1 = DecToBin(dec);
+     printf("%lld in decimal = %lld in binary\n", dec, bin1);
+     break;
+
+ case 'B':
+ case 'b':
+     printf("Enter a binary number: ");
+     scanf("%lld", &bin1);
+     dec = BinToDec(bin1);
+     printf("%lld in binary = %lld in decimalprintf\n");
+     break;
+
+ case 'C':
+ case 'c':
+
+
+
+
+
+
+
+            break;
+        case 'Q':
+        case 'q':
+            printf("The programme is terminated.\n");
+            break;
+        default:
+            printf("Invalid selection. Please enter again.\n");
+        }
 
 
  } while (auswahl1 != 'Q' && auswahl1 != 'q');