#include
using namespace std;
int multiply(int x,int res[],int res_size)
{ int prod;
int carry=0;
for(int i=0;i<res_size;i++)
{
prod=res[i]*x+carry;
res[i]=prod%10;
carry=prod/10;
}
while(carry)
{
res[res_size]=carry%10;
carry=carry/10;
res_size++;
}
return res_size;
}
void fact(int n)
{ int res[500];
res[0]=1;
int res_size=1;
for(int x=2;x<=n;x++)
{
res_size=multiply(x,res,res_size);
}
for(int i=res_size-1;i>=0;i--)
cout<<res[i];
}
int main() {
int n;
cin>>n;
fact(n);
return 0;
}