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#include <stdio.h>
#include <stdarg.h>

int sum(int n, ...)
{
    va_list ap;
    va_start(ap, n);

    int ans = 0;

    for (int i = 0; i < n; ++i)
        ans += va_arg(ap, int);

    va_end(ap);
    return ans;
}

int main()
{
    printf("%d\n", sum(4, 1, 3, 5, 7));
    return 0;
}

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#include <iostream>

using namespace std;

template<typename T>
T maxn(T a) { return a; }

template<typename T, typename... Args>
T maxn(T a, Args... rest)
{
    T b = maxn(rest...);
    return a > b ? a : b;
}

int main()
{
    cout << maxn<double>(1.1, 2.2, 3.3) << endl;
    return 0;
}

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#include <iostream>

using namespace std;

template<typename T, typename... Args>
T maxn(T a, Args... args)
{
    ((a = a > args ? a : args), ...);
    return a;
}

int main()
{
    cout << maxn<double>(1.1, 2.2, 3.3, 4.4) << endl;
    return 0;
}

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#include <utility>

template<typename T>
void wrapper(T&& x)
{
    process(std::forward<T>(x));
}

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template<typename... Args>
void print(Args&&... args) { std::cout << ... <<< std::forward<Args>(args) }