用高精度计算出S=1！+2！+3！+…+n！（n≤50）

program jiecheng(input,output);
const max=10000;
var i,j,n : integer;
sum,fac : array[1..max+1] of integer;
begin
assign(input,'sum9.in'); assign(output,'sum.out');
reset(input); rewrite(output);
read(n);
for i := 1 to max do sum[i] := 0;
for i := 1 to max do fac[i] := 0;
fac[1] := 1;
for i := 1 to n do
begin
for j := 1 to max do fac[j] := fac[j]*i;
for j := 1 to max do
begin
fac[j+1] := fac[j+1]+fac[j] div 10;
fac[j] := fac[j] mod 10;
end;
for j := 1 to max do sum[j] := sum[j]+fac[j];
for j := 1 to max do
begin
sum[j+1] := sum[j+1]+sum[j] div 10;
sum[j] := sum[j] mod 10;
end;
end;
i := max;
while sum[i]=0 do i := i-1;
for j := i downto 1 do write(sum[j]);
writeln;
close(input);
close(output);
end.