uses crt;
const
n=10;
var
xy:array [1..n,1..2] of real;
m: array [1..n] of real;
sx,kx,sy,ky:real;
i,j:integer;
xc,yc:real;
begin
writeln ('znachenie n=10');
for i:=1 to n  do begin
for j:=1 to 2 do
writeln ('x y',i,j,'=');
read (xy[i,1],xy[i,2]);
end;
for i:=1 to n do begin
writeln ('massa',i,'=');
read (m[i]);
end;
sx:=0;
sy:=0;
kx:=0;
ky:=0;
for i:=1 to n do begin
for j:=1 to 2 do begin
sx:=sx+(m[i]*xy[i,1]);
kx:=m[i]+kx;
sy:=sy+(m[i]*xy[i,2]);
ky:=m[i]+ky;
end;
end;
xc:=sx/kx;
yc:=sy/ky;
writeln ('Xc=',xc,'_Yc=',yc);
readln;
readkey
end.