() f()
{
    while 10 == 11 { int work; }

    while 20 == 21 {
        while 21 == 22 { int work; }
    }
    
    while 30 == 31 break;
    while 40 == 41 { while 41 == 42 break; }
    
    while 50 == 51 { }
}