#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>

int find_odd_element(int32_t arr[], size_t n) 
{
    int32_t res = 0;
    for (size_t i = 0; i < n; i++)
        res ^= arr[i];//А^B^A = A
    return res;
}
int main(void) {
    int32_t arr[] = {17,17,24,99,24,24,24};    
    size_t n = sizeof(arr) / sizeof(arr[0]);
    printf("The element is %" PRId32,
           find_odd_element(arr, n));
    return 0;
}