题解: ACdreamer orz!
code:
#include <cstdio>
#include <cstring>
using namespace std;
typedef long long ll;
const ll p =
1e9 +
7;
ll a[] ={
0,
2,
3,
5,
7,
13,
17,
19,
31,
61,
89,
107,
127,
521,
607,
1279,
2203,
2281,
3217,
4253,
4423,
9689,
9941,
11213,
19937,
21701,
23209,
44497,
86243,
110503,
132049,
216091,
756839,
859433,
1257787,
1398269,
2976221,
3021377,
6972593,
13466917,
20996011,
24036583,
25964951};
ll FastPowMod(ll a, ll b){
ll ret =
1 % p;
while(b){
if(b &
1) ret = ret * a % p;
a = a * a % p;
b >>=
1;
}
return ret;
}
int main(){
int n;
scanf(
"%d", &n);
printf(
"%lld\n", (FastPowMod(
2, a[n] -
1) + p -
1) % p);
return 0;
}
