#include<stdio.h>
#include<string.h>
char* toLowerCase(char* str);

int main(){
    printf("%s",toLowerCase("Hello"));
    return 0;
}


char* toLowerCase(char* str) {
    int i;
    for (i=0;i<strlen(str);i++){
        if(65<=str[i]&&str[i]<=90){
            str[i]=str[i]+32;
        }
    }
    return str;

}