diff --git a/grid.h.gch b/grid.h.gch
new file mode 100644
index 0000000000000000000000000000000000000000..46f01c9568d2b811dae39f2275fc70bef1e6063f
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diff --git a/grid.o b/grid.o
new file mode 100644
index 0000000000000000000000000000000000000000..8f87f4e598be981712cfd9741d518db66f5cb40e
Binary files /dev/null and b/grid.o differ
diff --git a/lib_gfx.h.gch b/lib_gfx.h.gch
new file mode 100644
index 0000000000000000000000000000000000000000..6989ada3cd99b3cf50490620c8d4a7cfe98070ec
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diff --git a/lib_gfx.o b/lib_gfx.o
new file mode 100644
index 0000000000000000000000000000000000000000..82f91ec7d4d9b0d5daa2b76beb0115695073cd0b
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diff --git a/main.c b/main.c
index 5068aa73e0bf35d768bbbc7f7b4c2c05e3e157aa..a0eaa5695b3285b0104cbfa3b9006049d69fb313 100644
--- a/main.c
+++ b/main.c
@@ -18,6 +18,7 @@ struct gfx_context_t *ctxt;
 void *keyboad_control(){
    
    while(1){
+      sem_wait(&lock);
    escape = gfx_keypressed();
    if (escape == SDLK_ESCAPE)
    {
@@ -25,6 +26,7 @@ void *keyboad_control(){
       exit(0);
       
    }
+   sem_post(&lock);
    }
    
 }
diff --git a/mask.h.gch b/mask.h.gch
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index 0000000000000000000000000000000000000000..dd0a3b766b311b86c903c2264836578eff5b4ede
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diff --git a/mask.o b/mask.o
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index 0000000000000000000000000000000000000000..f20998aa4d7f7a0ae6603e6b51432a0091e68017
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diff --git a/node.h.gch b/node.h.gch
new file mode 100644
index 0000000000000000000000000000000000000000..e2a56e0f1fc5ec04723021b97eafda41b8954660
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diff --git a/node.o b/node.o
new file mode 100644
index 0000000000000000000000000000000000000000..ef4c8e4f571362fd2b8f15e749d4060fd975314f
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diff --git a/vector.h.gch b/vector.h.gch
new file mode 100644
index 0000000000000000000000000000000000000000..fe1299cce24d4ae32c6e944104199ac625bfdae5
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diff --git a/vector.o b/vector.o
new file mode 100644
index 0000000000000000000000000000000000000000..4cd8e54050d8aef01523e20fbd28463d476778e1
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