C++ error: expected identifier before “(” token

if (d==28&&m==2)&&(a%400=0)
{
    d=29;
    m=2;
}
if (d==28) && (m==2) && (a%400!=0)
{
    d=1;
    m=m+1;
}
printf("%d%d%d",d,m,a);
getchar ();
return 0;
}

Excuse me :( can anyone give me a suggestion why the compiler shows the error? Please :(