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diff --git a/10_gdb/README b/10_gdb/README
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+For this assignment, you will be practicing with the basics
+of gdb.  You will want to use gdb extensively during the rest
+of the semester, as it is an incredibly useful tool to gather
+information during the debugging process.  For now, we 
+are just going to get started with some basic commands.
+Be sure you have done the readings and watched
+the video on gdb. 
+
+Enclosed, you will find game.c and the compiled
+binary game, for the most boring guessing game
+ever.  In the first round, the program thinks
+of a secret number (it is the same every single time),
+and asks you to guess it.  You get exactly one try.
+Note that it thinks of this number by calling
+getSecretNumber, which is not included in the source.
+
+If you get that right, in the second round,
+it thinks of another number.  It does this by repeatedly
+calling getOtherSN (also not shown in the source) and
+passing in different numbers.  It combines these results
+together, and does some math to combine the results into
+"total".  Afterwards, it asks you for your guess,
+and again, you have one chance.
+
+Before you proceed, try to "play" the game once by running:
+
+./game
+
+
+For example, I ran it and guessed 4:
+$ ./game 
+I'm thinking of a number...
+What number do you guess?
+4
+I'm sorry, that is not right.  You lose
+
+It would be pretty boring to play this game
+until you actually guess the right number and win,
+but fortunately, that isn't the point.  The
+point is to practice with gdb.
+
+In emacs, do
+
+ESC-x gdb
+
+Emacs will prompt you for how to run gdb (the default should be fine),
+and then give you the gdb prompt.  
+Use the "start" commmand to begin execution, then use "next"
+and "print" to find the secret number for round 1.
+When the program prompts you for this number, you should be able
+to guess the right one from the information you gathered.
+
+For round 2, you do not want to step through 5000+ iterations of the
+loop, so set a breakpoint after the loop, continue execution until you
+reach it, and the print out the variable "total".  Now you should
+be able to win round 2 instantly as well!
+
+Once you have found the two secret numbers, create a file called input.txt
+and place them in that file, one per line (round 1's secret number
+on the first line, and round 2's on the second line).
+
+You should be able to run
+
+./game < input.txt
+
+and "win" automatically.  That is, you should see this output (without
+having to type anything else):
+
+$ ./game < input.txt 
+I'm thinking of a number...
+What number do you guess?
+Correct! You win round1!
+Ok, time for round 2. I have another secret number.
+Your guess:
+You win round 2 also!
+
+
+When you finish, add input.txt to git, then commit, push, and grade.
+
+
diff --git a/10_gdb/game.c b/10_gdb/game.c
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+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/time.h>
+int getSecretNumber(void); //prototype, implemented elsewhere.
+
+int getOtherSN(int which); //prototype, implemented elsewhere.
+
+int main(void) {
+  int guessesMade = 0;
+  int yourGuess;
+  char buffer[1024];
+  int myNumber = getSecretNumber();
+
+  printf("I'm thinking of a number...\n");
+  printf("What number do you guess?\n");
+  if(fgets(buffer, 1024, stdin) == NULL) {
+    printf("Oh no, you are giving up?  You lose...\n");
+    return EXIT_FAILURE;
+  }
+  yourGuess = atoi(buffer);
+  if(yourGuess != myNumber) {
+    printf("I'm sorry, that is not right.  You lose\n");
+    return EXIT_FAILURE;
+  }
+  printf("Correct! You win round1!\n");
+  
+  int total = 0;
+  for (int i = 0; i <= 5678; i++) {
+    total = total ^ getOtherSN(i);
+  }
+  printf("Ok, time for round 2. I have another secret number.\n");
+  printf("Your guess:\n");
+  if(fgets(buffer, 1024, stdin) == NULL) {
+    printf("Oh no, you are giving up?  You lose...\n");
+    return EXIT_FAILURE;
+  }
+  yourGuess = atoi(buffer);
+  if (yourGuess == total) {
+    printf("You win round 2 also!\n");
+    return EXIT_SUCCESS;
+  }
+  printf("Sorry, you did not win the second round\n");
+  return EXIT_FAILURE;
+}
diff --git a/10_gdb/grade.txt b/10_gdb/grade.txt
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+++ b/10_gdb/grade.txt
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+Grading at Mon 29 Nov 2021 02:12:07 AM UTC
+Your file matched the expected output
+
+Overall Grade: PASSED
diff --git a/10_gdb/input.txt b/10_gdb/input.txt
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+++ b/10_gdb/input.txt
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+464384013
+938257400
+