int sum=0;
 int zancun=1;
while(w/10!=0)
{
    sum+=w%10*zancun;
    w/=10;
    zancun*=10;
}
return sum;

while(n>=100) n/=10; n%=10; return n;

int fun(int w)

{

    int n=w, k=1;

    while(n/10)

    {

        n=n/10;

        k=k*10;

    }

    return w-n*k;

}

	int sum;
	int m, n; 
	for(int j = 1;  m != 0; j = j * 10)
  	{
  		m = w;
  		m = m / j;
  		if((m % 10) != m)
  		{
			n = m % 10;
			sum += n * j;
		}

	}
 	return sum;

int t=w,mul=1;

while(t)

{ mul*=10;

t/=10; }

mul/=10;

return num%mul;

int b= 0;
int i = 1;
while(w >= 10){
    b = b + w % 10 * i;
    w /= 10;
    i *= 10;
}
return b;

int molecule=w;
    if(molecule<=10){
        return 0;
    }
    int denominator=1;
    while (molecule>10){
        molecule/=10;
        denominator*=10;
    }
    return w%denominator;

int molecule=w;
if(molecule<=10){
return 0;
}
int denominator=1;
while (molecule>10){
molecule/=10;
denominator*=10;
}
return w%denominator;

int rsl = 0;
int i = 1;
while(w >= 10){
    rsl = rsl + w % 10 * i;
    w /= 10;
    i *= 10;
}
return rsl;