for (a=0 a<10 a++) {
    //Stuff
    for (b=0 b<20 b++) {
        //Stuff
        for (c=0 c<30 c++) {
            // Stuff
            if (condition_to_break_all_loops) {
                b=20;
                a=10;
                break;
            }
        }
    }
}