#include <iostream>
#include <string>
#include <vector>
#include <ctype.h>

int main() {
    std::vector<std::string> words;
    words.push_back("hello");
    words.push_back("world");
    
    for (auto& i: words) {
        for (auto& j: i) {
            j = toupper(j);
        }
    }
    
    for (auto& i: words) {
        std::cout << i << std::endl;
    }
}