PE48

#include <iostream>
using namespace std;

int main()
{
    unsigned long long M = 10000000000ULL;
    int pow;
    unsigned long long res = 0ULL, temp;
    for(int i = 1; i <= 1000; i++)
    {
        pow = 1;
        temp = 1;
        while(pow <= i)
        {
            temp = (temp*i) % M;
            pow++;
        }
        res = (res + temp) % M;
    }
    cout << res << endl;
    return 0;
}