/**
 * Counts the occurrences of each character in a given string
 * @param {string} line - The input string to count characters from
 * @returns {object} - An object containing the counts of each character
 */
function getCharCounts(line = '') {
    return line
        .split('')
        .reduce((acc, char) => ({ ...acc, [char]: (acc[char] || 0) + 1 }), {});
}
 
// Read input line by line using the readline function
// Check if any character in each line appears exactly twice, and print the line if so
while ((line = readline())) {
    if (Object.values(getCharCounts(line)).some((count) => count === 2)) {
        print(line);
    }
}
 

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