tralling zero

#include<bits/stdc++.h>
using namespace    std;

#define flush        cin.ignore(numeric_limits<streamsize>::max(),'\n')
#define fasterio     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define NL           printf("\n")
#define fin          freopen("int.txt","r",stdin)
#define fout         freopen("ans2.txt","w",stdout)


//who cares? I want to give some scary looks to my code... XD//


typedef long long int       ll;
typedef double              dl;
typedef unsigned long long  ul;

// ------------------------------------Constants-------------------------------------//

#define pi           (acos(-1.0)) //3.1415926535897932384626
#define mx           7500000
#define dpoint(x)    fixed<<setprecision(x)


int main()
{
   //fin;
   //fout;
   vector<int>num;

    int sum=0;

    for(int n=1; n<100; n++){
        do{
            n = n/5;
            sum = sum+n;
        }while(n>0);
        num.push_back(sum);
    }

   cout<<num[10]<<endl;
   return 0;

}