Covert binary number to its decimal equivalent

/*
Program to convert the binary number to its decimal equivalent
*/

#include<stdio.h>
#include<stdlib.h>
#include<math.h>

main()
{
    int binnum,decimal=0,rem,i=0;
    printf("Enter the binary number: ");
    scanf("%d",&binnum);
   
    while(binnum!=0)
    {
        rem=binnum%10;
        if(rem>1){
            printf("\nNot Binary number\n");
            exit(1);
        }
        if(rem==0)
            i++;
        else
        {
            decimal+=pow(2,i);
            i++;
        }       
        binnum/=10;
    }
    printf("Decimal Equivalent is : %d\n",decimal);
}