const row = require('fs').readFileSync('/dev/stdin','utf8').split('\n');
const str = row[0].split('');
const result = str.reduce((acc, cur)=> {
    if(/[A-Z]/.test(cur)){
        return `${acc}${cur.toLowerCase(cur)}`;
    }else {
        return `${acc}${cur.toUpperCase(cur)}`;
    }
},'');

console.log(result);