CA-LAB-program-program for binary multiplication

#include<stdio.h>
int binaryAddition(int,int);
int main(){
long int binary1,binary2,multiply=0;
int digit,factor=1; 
printf("Enter any first binary number: "); 
scanf("%ld",&binary1);
printf("Enter any second binary number: "); 
scanf("%ld",&binary2); 
while(binary2!=0){
digit = binary2 %10;
if(digit ==1){
binary1=binary1*factor;
multiply = binaryAddition(binary1,multiply);
} 
else
binary1=binary1*factor;
binary2 = binary2/10; 
factor = 10;
}
printf("Product of two binary numbers: %ld",multiply); 
return 0;
}
int binaryAddition(int binary1,int binary2){ 
int i=0,remainder = 0,sum[20];
int binarySum=0;
while(binary1!=0||binary2!=0){ 
sum[i++] = (binary1 %10 + binary2 %10 + remainder ) % 2;
remainder = (binary1 %10 + binary2 %10 + remainder ) / 2; 
binary1 = binary1/10;
binary2 = binary2/10;
} 
if(remainder!=0)
sum[i++] = remainder; 
--i; while(i>=0) 
binarySum = binarySum*10 + sum[i--];
return binarySum;
}