import java.util.*;
import java.lang.*;
import java.io.*;
 
class Ideone {
	public static void main (String[] args) throws java.lang.Exception {
		System.out.println(hexToAscii(
			"51d37bdd871c9e1f4d5541be67a6ab625e32028744d7d4609d0c37747b40cd2d"
		));
	}
 
	public static String hexToAscii(String hex) {
    	StringBuilder sb = new StringBuilder();
    	// StringBuilder temp = new StringBuilder();
 
    	for(int i = 0; i < hex.length() - 1; i += 2){
    		String output = hex.substring(i, (i + 2));
        	int decimal = Integer.parseInt(output, 16);
        	sb.append((char)decimal);
 
        	// temp.append(decimal);
    	}
 
    	return sb.toString();
	}
}

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