#include <stdio.h>

int main()

{

long long int a,b,min;

scanf("%lld%lld",&a,&b);

if(a>=b){

min=b;

}else{

min=a;

}

unsigned long long int num=1;

for(int i=1;i<=min;i++){

num*=i;

}

printf("%llu\n",num);

return 0;

}