Write a function that creates an object with each (key, value) pair being the (lower case, upper case) versions of a letter, respectively.

Examples

mapping(["x", "a", "v", "i", "e", "r"]) ➞ { "x"="X", "a"="A", "v"="V", "i"="I", "e"="E", "r"="R" }

mapping(["t", "e", "s", "h", "a"]) ➞ { t=T, e=E, s=S, h=H, a=A }

mapping(["p", "s"]) ➞ { "p"="P", "s"="S" }

mapping(["a", "b", "c"]) ➞ { "a"="A", "b"="B", "c"="C" }

mapping(["a", "v", "y", "z"]) ➞ { "a"="A", "v"="V", "y"="Y", "z"="Z" }

mapping(["d", "x", "t", "s"]) ➞ { "d"="D", "x"="X", "t"="T", "s"="S" }

Notes

All of the letters in the input list will always be lowercase.