create a for loop that iterates through all possible allcaps strings of length 6 in csharp

main.cs
for(char c1 = 'A'; c1 <= 'Z'; c1++) {
    for(char c2 = 'A'; c2 <= 'Z'; c2++) {
        for(char c3 = 'A'; c3 <= 'Z'; c3++) {
            for(char c4 = 'A'; c4 <= 'Z'; c4++) {
                for(char c5 = 'A'; c5 <= 'Z'; c5++) {
                    for(char c6 = 'A'; c6 <= 'Z'; c6++) {
                        string allCapsString = $"{c1}{c2}{c3}{c4}{c5}{c6}";
                        // code block to be executed for each all-caps string
                    }
                }
            }
        }
    }
}
514 chars
15 lines