Reference从函数返回的变量给出了奇怪的值

I've been working on a hangman game lately, and this function supposedly checks for a letter that the user inputs in an array (Containing a pre-defined word such as "BUILDING") and adds on a Counter (Count) if the letter exists or decreases the lives (Which start at 5 -defined in the main function-) if it doesn't exist. I've been working on a hangman game lately, and