How to perform addition,subtraction of 2 numbers without using addition and subtraction operators?

main()
{
int a,b,c;
printf("enter 2 nos");
scanf("%d%d",&a,&b);
for(i=1;a>0;i++)
a=a-1;
for(j=i;b>0;j++)
b=b-1;
printf("addition of %d+%d:%d",a,b,(j-1));
}