IP Address class Program in c

#include<stdio.h>
int main()
{
    int a[50],b[50],i,j,n=0;
    printf("Enter the IP Address:");
    for(i=0;i<4;i++)
    {
       scanf("%d",&a[i]);
       if(a[i]<0||a[i]>255)
       {
           n++;
       }
    }
    if(n==0)
    {
        printf("This is a valid IP address: ");
    }
    else
     printf("This is invalid IP address: ");

    for(i=0;i<4;i++)
    {
       printf("%d",a[i]);

    }
    printf("\n");

    i=0;
    if(a[i]>=0 && a[i]<=127)
    {
      printf("It is A class IP");
    }

    else if(a[i]>127 && a[i]<=191)
    {
        printf("It is B class IP");
    }

    else if(a[i]>191 && a[i]<=223)
    {
        printf("It is C class IP");
    }

     else if (a[i]>223 && a[i]<=239)
     {
         printf("It is D class IP");
     }

    else if (a[i]>239 && a[i]<=255)
    {
        printf("It is E class IP");
    }



}