OJ Board

int main()
{
//freopen("10212.in","r",stdin);
unsigned n,m;
while(cin>>n && cin>>m)
{
unsigned int f1=n;
if(f1==0)
f1=1;
for(unsigned int i=1;i<n;i++)
{
f1=f1*i;
}
unsigned int f2=n-m;
if(f2==0)
f2=1;

for(i=1;i<n-m;i++)
{
f2=f2*i;
}
unsigned int f=f1/f2;
if(f%10!=0)
{
f=f%10 ...