.i1 {
    background-image: url(../images/alex.jpg);
}

.i2 {
    background-image: url(../images/alisha.jpg);
}

.i3 {
    background-image: url(../images/alvin.jpg);
}

.i4 {
    background-image: url(../images/anakin.jpg);
}

.i5 {
    background-image: url(../images/archie.jpg);
}

.i6 {
    background-image: url(../images/arya.jpg);
}