diff --git a/balloon/example/brainfuck.nas b/balloon/example/brainfuck.nas
deleted file mode 100644
index eefba3c..0000000
--- a/balloon/example/brainfuck.nas
+++ /dev/null
@@ -1,71 +0,0 @@
-
-var resource=[];
-var data=[];
-var ptr=0;
-for(var i=0;i<1024;i+=1){append(data,0);}
-
-var input_file=func(str)
-{
-    resource=[];
-    var res=read(str);
-    for(var i=0;i<size(res);i+=1)
-    {
-        var ch=chars(res[i]);
-        for(var j=0;j<size(ch);j+=1){append(resource,ch[j]);}
-    }
-    return;
-};
-var runloop=func(times,begin)
-{
-    var ends=begin;
-    for(var t=0;t<times;t+=1)
-    {
-        for(var i=begin;i<size(resource);i+=1)
-        {
-            if(resource[i]=='+'){data[ptr]+=1;}
-            else if(resource[i]=='-'){data[ptr]-=1;}
-            else if(resource[i]=='>'){ptr+=1;}
-            else if(resource[i]=='<'){ptr-=1;}
-            else if(resource[i]=='.'){print(data[ptr],' ');}
-            else if(resource[i]==','){data[ptr]=num(input());}
-            else if(resource[i]=='[')
-            {
-                var t_ends=runloop(data[ptr],i+1);
-                i=t_ends;
-            }
-            else if(resource[i]==']'){ends=i;break;}
-            else{print('error token: ',resource[i],'\n');}
-        }
-    }
-    return ends;
-};
-var runtime=func()
-{
-    for(var i=0;i<1024;i+=1){data[i]=0;}
-    ptr=0;
-    for(var i=0;i<size(resource);i+=1)
-    {
-        if(resource[i]=='+'){data[ptr]+=1;}
-        else if(resource[i]=='-'){data[ptr]-=1;}
-        else if(resource[i]=='>'){ptr+=1;}
-        else if(resource[i]=='<'){ptr-=1;}
-        else if(resource[i]=='.'){print(data[ptr],' ');}
-        else if(resource[i]==','){data[ptr]=num(input());}
-        else if(resource[i]=='[')
-        {
-            var ends=runloop(data[ptr],i+1);
-            i=ends;
-        }
-        else{print('error token: ',resource[i],'\n');}
-    }
-    return;
-};
-while(1)
-{
-    print("bf> ");
-    var filename=input();
-    if(filename=='exit'){break;}
-    input_file(filename);
-    runtime();
-    print('\n');
-}