program my; const max = 2550; type long = record sign : char; len : word; number : array[1..max+1] of shortint; end; var a,b,c,r,x,y : long; i,n,res : longint; procedure input(var x : long); var i : word; s : char; begin if (s>='0') and (s<='9') then begin read(s); x.sign := '+'; x.len := 1; x.number[1] := ord(s)-ord('0'); end; while not eoln do begin read(s); if (s>='0') and (s<='9') then begin inc(x.len); x.number[x.len] := ord(s)-ord('0'); end; end; for i := x.len downto 1 do x.number[max-x.len+i] := x.number[i]; for i := 1 to max-x.len do x.number[i] := 0; readln; end; procedure output(const x: long); var i : word; begin for i := max-x.len+1 to max do write(x.number[i]); writeln; end; function comp_abs(const a,b : long) : shortint; var i : word; res : shortint; begin {// a.number[max+1] := 1; b.number[max+1] := 2;} i := 1; while (i <= max) and (a.number[i] = b.number[i]) do inc(i); if i>max then res := 0 else if a.number[i] <b.number[i] then res:= -1 else res := 1; comp_abs := res; end; function compare(const a,b : long) : shortint; begin if a.sign=b.sign then if a.sign='-' then compare:=-comp_abs(a,b) else compare:= comp_abs(a,b)else if (a.sign='-') then compare := -1 else compare := 1; end; function longLen(const a : long) : word; var I : word; begin i :=1; {// a.number[max+1] := 1;} while (i <= max) and (a.number[i]=0) do inc(i); if i <=max then longLen:= max-i+1 else longLen := 1; end; procedure plus_abs(const a,b : long; var res : long); var i : word; p : byte; s : shortint; begin p := 0; for i := max downto 1 do begin s := a.number[i]+b.number[i]+p; res.number[i] := s mod 10; p := s div 10; end; res.len := longLen(res); end; procedure shift(var a : long;k : word); var i : word; begin for i := 1 to max-k do a.number[i] := a.number[i+k]; for i := max-k+1 to max do a.number[i] := 0; end; function comp_0(const x: long) : boolean; begin if (x.number[max-longLen(x)+1] =0) and (x.number[max]=0) then comp_0 := true else comp_0 := false; end; procedure minus_abs(const a,b : long;var res : long); var i: word; z : byte; begin z := 0; for i := max downto 1 do begin res.number[i] := a.number[i]-b.number[i]-z; if res.number[i]<0 then begin inc(res.number[i],10); z := 1; end else z := 0; end; res.len := longLen(res); end; procedure div_mod(const a,b : long;var rest: long); var i,p,nd : word; begin for i := 1 to max do begin rest.number[i] := 0; end; begin if a.len<b.len then nd := a.len else nd := b.len; for i := 1 to nd do rest.number[max-nd+i]:= a.number[max-a.len+i]; if a.len>=b.len then for p := max-a.len+b.len to max do begin rest.len := longLen(rest); while comp_abs(rest,b)>=0 do begin minus_abs(rest,b,rest); end; if p<max then begin shift(rest,1); rest.number[max] := a.number[p+1]; end; end; rest.len := longLen(rest); end; end; procedure _div(const a,b : long;var quot,rest: long); var i,p,nd : word; s : byte; begin for i := 1 to max do begin quot.number[i] := 0; rest.number[i] := 0; end; if comp_0(b) then writeln('division by zero') else begin if a.len<b.len then nd := a.len else nd := b.len; for i := 1 to nd do rest.number[max-nd+i]:= a.number[max-a.len+i]; if a.len>=b.len then for p := max-a.len+b.len to max do begin s := 0; rest.len := longLen(rest); while comp_abs(rest,b)>=0 do begin minus_abs(rest,b,rest); inc(s); end; shift(quot,1); quot.number[max] := s; if p<max then begin shift(rest,1); rest.number[max] := a.number[p+1]; end; end; quot.len := longlen(quot); rest.len := longLen(rest); end; if a.sign=b.sign then quot.sign := '+' else quot.sign:= '-'; rest.sign := a.sign; end; procedure _gcd(var a : long;b : long; var c : long); var X: long; begin while (comp_0(a) <> true) and (comp_0(b) <> true) do begin if comp_abs(a,b)>0 then begin div_mod(a,b,X); a := X; end else begin div_mod(b,a,X); b := X; end; end; plus_abs(a,b,c); end; begin input(x); input(y); if (longLen(x)>=2550) or (longLen(y)>=2550) then writeln(0) else begin _gcd(x,y,a); output(a); end; end.