Thread: Why this program show me unlimited number of ans?

When i run this program it show me unlimited number of same ans.
But The ans are correct.
so, how can i avoid this problem. thanks.

Code:

/*Write a program that will finds the largest in a series ofnumbers entered by the user. The program must prompt the 
user to enter one by one. When the user enters 0 ,
the program must display the largest nonnegative number entered:
    */
//CREATED BY: ABHIJIT DAS
//DATE:1.7.2012
//VER: 1.0


#include<stdio.h>
#include<conio.h>
main()


{
     float a, b, c;
     printf("Enter a number:\n");
     scanf("%f", &a);
     while(a == 0)
     {
             printf("You must enter a number. Please enter a number\n");
             scanf("%f", &a);
             }
             if(a != 0)
             {
                  c = +a;
                  }
                  printf("Enter a number:\n");
                  scanf("%f", &b);
                  if(b == 0)
                  {
                       printf("The largest number is %f\n", c);
                       }
                       while(a> 0 && b>0)
                       {
                                if(b!= 0 && b>c)
                                {
                                       c = +b;
                                       }
                                       printf("Enter a number:\n");
                                       scanf("%f", &a);
                                       while(a == 0)
                                       {
                                            printf("The largest number is :%f", c);
                                            }
                                       if(a != 0 && a>c)
                                       {
                                            c = +a;
                                            }
                                            printf("Enter a number:\n");
                                            scanf("%f", &b);
                                            }
                                            while(a == 0 || b == 0)
                                            {
                                                    printf("The largest number is %f\n", c);
                                                    }
                                                    
                                                    getch();
                                                    return 0;
                                                    }