#include

#include

int C(int,int);

int main()

{

int x,y;

scanf(＂%d,%d＂,&x,&y);

printf(＂%d＂,C(x,y));

}

int C(int n,int m) /*求n个取m个组合数*/

{

int i,j,s1,s2,s;

for (i=1,s1=1;i<=n;i++)

{

s1=s1*i;

}

for (j=1,s2=1;j<=m;j++)

{

s2=s2*j;

}

s=s1/s2;

return s;

}