diff --git a/cv3/program.c b/cv3/program.c
index 9f39b2b..12e1807 100644
--- a/cv3/program.c
+++ b/cv3/program.c
@@ -1,9 +1,9 @@
-#include <assert.h> 
 #include <stdio.h> 
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
 
-#define STACK_SIZE 100
+#define STACK_SIZE 10
 
 struct stack {
     float values[STACK_SIZE];
@@ -11,17 +11,29 @@ struct stack {
 };
 
 void push(struct stack* stack,float values){
-    assert(stack->size < STACK_SIZE);
-    stack->values[stack->size] = values;
-    stack->size += 1;
+    if(stack->size < 10){
+        stack->values[stack->size] = values;
+        stack->size += 1;   
+    }
+    else{
+        printf("full stack\n");
+        exit(0);
+
+    }
 }
 
 float pop(struct stack *stack){
-    assert(stack->size > 0);
-    float values = stack->values[stack->size-1]; 
-    stack->size -= 1; 
-    return values; 
+    if(stack->size > 0){
+        float value = stack->values[stack->size-1];
+        stack->size -= 1;
+        return value;
+    }
+    else{
+        printf("not enough operands\n");
+        exit(0);
+    }
 }
+
 void print_stack(struct stack *stack){
     int i;
     int len = stack->size - 1;
@@ -30,9 +42,8 @@ void print_stack(struct stack *stack){
     }
     if(stack->size != 0){
         printf("%0.2f ", stack->values[i]);
-    }
-    printf("\n");
-
+        printf("\n");
+    }   
 }
 
 
@@ -40,44 +51,55 @@ int main() {
     struct stack mystack;
     memset(&mystack, 0, sizeof(struct stack));
     int i = 0;
-    float z;
-    for(i = 0; i < 10000; i++){
+    for(i = 0; i < 100; i++){
+
         char line[10];
         char *x = fgets(line, 10, stdin);
         float r = 0;
-         
-        if(!isdigit(line[0]) && line[0] != '+' && line[0] != '*' && line[0] != '/' && line[0] != '-'){
-            printf("no input");
-            return 0;
-        }       
+        float z = 0;
         
-        if(line[0] == '+'){
-            r = pop(&mystack) + pop(&mystack); 
-        }
-        else if(line[0] == '-'){
-            z = pop(&mystack);
-            r = pop(&mystack) - z;
-        }
-        else if(line[0] == '*'){
-            r = pop(&mystack) * pop(&mystack);
-        }
-        else if(line[0] == '/'){
-            z = pop(&mystack);
-            if(z != 0.0){
-                r = pop(&mystack) / z;
+        if(line[1] != 0 && x != NULL){
+
+        
+            if(!isdigit(line[0]) && line[0] != '+' && line[0] != '*' && line[0] != '/' && line[0] != '-'){
+                printf("bad input\n");
+                return 0;
+            }       
+
+            if(line[0] == '+'){
+                r = pop(&mystack) + pop(&mystack);
             }
+            else if(line[0] == '-'){
+                z = pop(&mystack);
+                r = pop(&mystack) - z;
+            }
+            else if(line[0] == '*'){
+                r = pop(&mystack) * pop(&mystack);
+            }
+            else if(line[0] == '/'){
+                z = pop(&mystack);
+                if(z == 0){
+                    printf("division by zero\n");
+                    return 0;
+                }
+                else {
+                    r = pop(&mystack) / z;
+                }
+            }
+
+    
+            else {
+                r = strtof(line,&x);
+            } 
+
+            push(&mystack,r);
+            print_stack(&mystack);
         }
-
-        else {
-            r = strtof(line,&x);
-        }      
-        
-        push(&mystack,r);
-        print_stack(&mystack);
-            
+        else{
+            printf("no input\n");
+            return 0;
+        }    
     }
-
-
-
+      
     return 0;
 }