/**/
pre.c4 {
    margin-top: 6em
    }
table.c3 {
    border: 2px black solid;
    margin: auto auto;
    max-width: 50%;
    padding: 1%
    }
img.c2 {
    border: none
    }
pre.c1 {
    margin-bottom: 6em
    }
/**/