def find_maximum(arr):
    if not arr:
        return None
    max_value = arr[0]
    for num in arr:
        if num > max_value:
            max_value = num
    return max_value
            

#include 
#include 
#include 

int find_maximum(const std::vector& arr) {
    if (arr.empty()) return std::numeric_limits::min();
    int max_value = arr[0];
    for (int num : arr) {
        if (num > max_value) {
            max_value = num;
        }
    }
    return max_value;
}

int main() {
    std::vector arr = {1, 5, 3, 9, 2};
    std::cout << "Maximum value: " << find_maximum(arr) << std::endl;
    return 0;
}