Power

#include <bits/stdc++.h>
using namespace std;
int fact(int x) {
    if(x==1||x==0) return 1;
    else{
        return x * fact(x-1);
    }
}
long double power(long double x, int y) {
    long double u = 1;
    for(int i=0;i<y;i++) {
        u = u * x;
    }
    return u;
}
int main() {
    long double a = 4 * log(4);
    long double sum = 0;
    // cout << fact(5);
    // cout << power(2.5,4);
    long double fact = 1;
    for(int i = 0;i<50;i++) {
        fact = fact * (long double)(i+1);
        sum+= ((long double)(power(a,i) / (long double)fact));
    }
    cout << sum;
}