program astro;
var tstr : string[5];
    j : integer;
    i : longint;
    t, p : array[1..2] of integer;
    period, ok : boolean;
    time : array[1..2, 0..1439] of longint;

begin
    readln(tstr); val(tstr[1]+tstr[2], i, j); t[1] := i*60;
                  val(tstr[4]+tstr[5], i, j); t[1] := t[1] + i;
    readln(tstr); val(tstr[1]+tstr[2], i, j); t[2] := i*60;
                  val(tstr[4]+tstr[5], i, j); t[2] := t[2] + i;
    readln(tstr); val(tstr[1]+tstr[2], i, j); p[1] := i*60;
                  val(tstr[4]+tstr[5], i, j); p[1] := p[1] + i;
    readln(tstr); val(tstr[1]+tstr[2], i, j); p[2] := i*60;
                  val(tstr[4]+tstr[5], i, j); p[2] := p[2] + i;

    ok := false;
    time[1, t[1]] := 1;
    period := false;
    i := 1;
    repeat
        t[1] := t[1] + p[1]; if t[1] > 1439 then begin
        t[1] := t[1] - 1440; i := i + 1; end;
        if time[1, t[1]] <> 0 then period := true
        else time[1, t[1]] := i;
    until period;
    time[2, t[2]] := 1;
    period := false;
    i := 1;
    repeat
        t[2] := t[2] + p[2]; if t[2] > 1439 then begin
        t[2] := t[2] - 1440; i := i + 1; end;
        if time[2, t[2]] <> 0 then period := true
        else time[2, t[2]] := i;
    until period;
    i := 1;
    j := 0; ok := false;
    repeat {write(time[1, i], ' --- ', time[2, i]); readln;}
    i := i + 1;
    if (time[1,i] = time[2,i]) and not (time[1,i] = 0) then begin
        if (time[1,i] < time[2, j]) or (not ok) then begin
            j := i; ok := true; end;
    end;
    until i = 1439;
    if ok then begin
        case time[1,j] mod 7 of
            1 : writeln('subota');
            2 : writeln('nedjelja');
            3 : writeln('ponedjeljak');
            4 : writeln('utorak');
            5 : writeln('srijeda');
            6 : writeln('cetvrtak');
            0 : writeln('petak');
        end;
        if j div 60 < 10 then write('0', j div 60)
        else write(j div 60);
        if j mod 60 < 10 then writeln(':0', j mod 60)
        else writeln(':', j mod 60);
    end
    else writeln('nikad');
end.