Input

2

Output

2

        
 

Hint

1. For N = 2, S(1) = S(2) = 1. 2. The input file consists of multiple test cases.

Sample Input

2

Sample Output

2

        
 

Hint

1.  For N = 2, S(1) = S(2) = 1.

2.  The input file consists of multiple test cases. 

        
 

 題意：

  題目讓我們求的是2的N次冪，但由於N過大，所以需要用到尤拉降冪公式。

#include <iostream>
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <algorithm>
#include <limits>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#define lowbit(x) ( x&(-x) )
using namespace std;
typedef long long ll;
const ll mod=1e9+7;
const ll phi=1e9+6;
ll ans=0;
char s[100005];
ll mi(ll x, ll y)
{
    ll res=1;
    while(y)
    {
        if(y&1)
        {
            res=res*x%mod;
        }
        x=x*x%mod;
        y>>=1;
    }
    return res;
}
int main()
{
    while(scanf("%s",s)!=EOF)
    {
        ans=0;
        int len=(int)strlen(s);
        for(int i=0; i<len; i++)
        {
            ans=(ans*10+s[i]-'0')%phi;
        }
        printf("%lld\n",mi(2, (ans+phi-1)%phi));
    }
    return 0;
}