Added negative reading number functionality to read_number(), so that…

… it knows when they input a negative bet

blackjackfolder/cardsystem.c

@@ -5,10 +5,12 @@
 
 long long read_number() {
     long long number = 0;
+    int negative_flag = 0;
 
     char c = getchar();
 
     while (!(c >= '0' && c <= '9')) {
+        if(c=='-') negative_flag = 1;
         c = getchar();
     }
 
@@ -22,6 +24,8 @@ long long read_number() {
     else if(c=='m' || c=='M') number *= 1000000;
     else if(c=='b' || c=='B') number *= 1000000000;
 
+    if(negative_flag) number *= -1;
+
     return number;
 }
 
@@ -231,4 +235,4 @@ int game(char name[], int deck[][4][14], int *played_cards, int double_down, int
         }
     }
 
-}
+}