rt

以下是程序：

var

n,m,i,j,k,l:longint;

x,y:Array[1..2000] of int64;

z:Array[1..200,0..2000] of int64;

f:array[0..2000] of int64;

begin

read(n,m);

for i:=1 to m do

read(x[i],y[i]);

for i:=1 to n do

begin

for j:=1 to n do

begin

z:=x[i];

for k:=1 to y[i] do

z:=z*j;

end;

end;

for i:=0 to n do

f[i]:=z[1,i];

f[0]:=0;

for i:=2 to m do

for j:=n downto 1 do

for k:=0 to j do

if f[j-k]+z