12 lines
215 B
C++
12 lines
215 B
C++
#include<bits/stdc++.h>
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using namespace std;
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typedef long long LL;
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LL n, ans;
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int main() {
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cin >> n;
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ans = n * (n - 1) / 2 * (n - 2) / 3 * (n - 3) / 4;
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printf("%lld\n", ans);
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return 0;
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} |