func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, p, q;   unsigned int C[132];   int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }   int a[132];   void Init() {     C[0] = 1;     for (int i = 1; i <= min(p, n - 1); ++i) {       a[0] = 0;       for (int j = 0; j < i; ++j) a[++a[0]] = n - j;       for (int k = 1; k <= i; ++k) {         int x = k;         for (int j = 1; j <= a[0] && k != 1; ++j) {           int Gcd = gcd(x, a[j]);           a[j] /= Gcd, x /= Gcd;         }       }       C[i] = 1;       for (int j = 1; j <= a[0]; ++j) C[i] = C[i] * a[j];     }   }   int main() {     scanf( %d%d%d , &n, &p, &q), Init();     unsigned int ans = 0;     for (int i = 1; i <= q; ++i) {       unsigned int tmp = 0, now = 1;       for (int j = 0; j <= min(p, n - 1); ++j, now = now * i) tmp += C[j] * now;       ans ^= tmp * i;     }     printf( %u n , ans);     return 0;   }   