import std.stdio, std.conv, std.string, std.array, std.range, std.algorithm, std.container;
import std.math, std.random, std.bigint, std.datetime, std.format;
void main(string[] args){ if(args.length > 1) if(args[1] == "-debug") DEBUG = 1; solve(); } bool DEBUG = 0; 
void log(A ...)(lazy A a){ if(DEBUG) print(a); }
void print(){ writeln(""); } void print(T)(T t){ writeln(t); } void print(T, A ...)(T t, A a){ write(t, " "), print(a); }
string unsplit(T)(T xs){ return xs.array.to!(string[]).join(" "); }
string scan(){ static string[] ss; while(!ss.length) ss = readln.chomp.split; string res = ss[0]; ss.popFront; return res; }
T scan(T)(){ return scan.to!T; } T[] scan(T)(int n){ return n.iota.map!(i => scan!T()).array; }
T lowerTo(T)(ref T x, T y){ if(x > y) x = y; return x; } T raiseTo(T)(ref T x, T y){ if(x < y) x = y; return x; }

// ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- //

void solve(){
    string s = scan;
    string ans;
    foreach(c; s){ if(c == '?') ans ~= 'D'; else ans ~= c; }
    ans.print;
}

