How to remove characters in a string that are in pairs?

Question

C++ / C#

Hello everyone, I need a hello)
Task: there is a string "abvgd" - from it you need to remove the lines that stand in a double place. Tobish should get "abvgd" -> "avd".

Answer 1

string abcde = "abcde";

for (int i = 1; i < abcde.length(); i++) {
    abcde.erase(i, 1);
}

cout << abcde << endl;