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#include <iostream>
#include <vector>
using namespace std;

vector<int> memo(501, -1);

int countSequences(int n) {
if (n == 1) return 1;
if (memo[n] != -1) return memo[n];

int res = 1; // 包含序列[n]本身
for (int i = 1; i <= n/2; ++i) {
    res += countSequences(i);
}
return memo[n] = res;

}

int main() {
int n;
cin >> n;
cout << countSequences(n);
return 0;
}