Your task is to convert each word at an even position to uppercase and return the modified string.

1. Split the input string into an array of words using the split(" ") method from the String class.
2. Create an object for building the result string step by step using the StringBuilder class.
3. Loop through all elements of the array.
4. Inside the loop, check if the index is even using the remainder operator % with 2.
5. If the index is even, convert the corresponding word to uppercase using the toUpperCase() method.
6. If the index is odd, append the word as is.
7. After the loop, convert the result to a string using the toString() method.