#include<iostream> // cin\cout\endl #include<ctime> //scanf()\printf() #include<cstdlib> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int n,sum=1; cin>>n; for(int i=1;i<=n;i=i+1) sum*=i; cout<<sum; return 0; }