#include<iostream> #include<cstdio> //scanf()\printf() #include<cstring> #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ long long n,sum=1; cin>>n; for(int i=1;i<=n;i++){ sum=sum*i; } cout<<sum; return 0; }