miz.cpp

#include <iostream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <algorithm>
#include <string>
#include <set>
using namespace std;
typedef long long int ll;
#define rep(i,n) for(int i=0; i<(int)(n);i++)
ll n, temp;
int main(){
  cin >> n;
  vector<int> d[n+1];
  temp = 1;
  for(int i = 1; i <= n;i++){
    temp *= i;
    ll a = temp;
    bool er = false;
    for(int j=0; a>=0;j++, a/=10){
      int key = a%10;
      if(j == 0 && key == 0) er = true;
      if(key!=0) er = false;
      if(er==false)d[i].push_back(key);
      if(d[i].size()==9) break;
    }
    temp = 0;
    for(int j=1,k=0; k < d[i].size(); j*=10, k++){
      temp += j*d[i][k];
    }
  }
  bool p = false;
  int k = d[n].size()-1;
  for(int i = k; i>=0;i--){
    if(i==k && d[n][i] ==0) p = true;
    if(d[n][i] != 0) p = false;
    if(p==false)cout << d[n][i];
  }
  return 0; 
}