34 lines
834 B
Plaintext
34 lines
834 B
Plaintext
const
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step:integer=0;
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chars:array[0..15] of char=('0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F');
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var
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digit:array[char] of integer;
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i,n,g:integer;
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m,s:string;
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ok:boolean;
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begin
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for i:=0 to 9 do digit[char(ord('0')+i)]:=i;
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for i:=0 to 5 do digit[char(ord('A')+i)]:=i+10;
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readln(n);
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readln(s);
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for i:=1 to length(s) do s[i]:=upcase(s[i]);
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repeat
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ok:=true;
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for i:=1 to length(s) div 2 do
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if s[i]<>s[length(s)+1-i] then ok:=false;
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if ok then break;
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inc(step);
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m:=s; g:=0;
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for i:=length(m) downto 1 do
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begin
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s[i]:=chars[(digit[m[i]]+digit[m[length(m)+1-i]]+g) mod n];
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g:=(digit[m[i]]+digit[m[length(m)+1-i]]+g) div n;
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end;
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if g>0 then s:=chars[g]+s;
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until step>=30;
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if ok then
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writeln('STEP=',step)
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else
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writeln('Impossible');
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end.
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