potenza

#include <stdio.h>
#include <vector>
#include <algorithm>

int my_pow(int a, int b)
{
    int i = 0;
    int c = a;
    while(i<b)
    {
        c*=a;
        i++;
    }
    return c;
}

int alloca(int N)
{
    std::vector<int> P;
    for(int i=1; i<N; i++)
    {
        for(int j=1; j<N; j++)
        {
            int a = my_pow(i,j);
            if(a<=N) P.push_back(a);
        }
    }
    return *std::max_element(P.begin(),P.end());
}


int main()
{
    FILE *fr, *fw;
    int N;

    fr = fopen("input.txt", "r");
    fw = fopen("output.txt", "w");

    fscanf(fr, "%d", &N);
    fprintf(fw, "%d\n", alloca(N));

    fclose(fr);
    fclose(fw);
    return 0;
}