.wrapper {
    width: 570px;
    height: 570px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.a {
    background-color: #999;
    width: 180px;
    height: 180px;
}

.a:nth-child(n) {
    display: flex;
}

.a:nth-child(2) {
    justify-content: center;
}

.a:nth-child(3) {
    justify-content: end;
}

.a:nth-child(4) {
    align-items: center;
}

.a:nth-child(5) {
    justify-content: center;
    align-items: center;
}

.a:nth-child(6) {
    justify-content: end;
    align-items: center;
}

.a:nth-child(7) {
    align-items: end;
}

.a:nth-child(8) {
    justify-content: center;
    align-items: end;
}

.a:nth-child(9) {
    justify-content: end;
    align-items: end;
}

.b {
    background-color: orange;
    width: 60px;
    height: 60px;
}