import std.algorithm, std.array, std.container, std.range;
import std.numeric, std.math, std.bigint, std.bitmanip, std.random;
import std.string, std.conv, std.stdio, std.typecons;

void main()
{
  auto s = readln.chomp.dup;

  foreach (ref c; s) {
    if (c >= 'A' && c <= 'Z')
      c = ((c - 'A') + 'a').to!char;
    else if (c >= 'a' && c <= 'z')
      c = ((c - 'a') + 'A').to!char;
  }

  writeln(s);
}