    import std.stdio, std.string, std.array, std.conv, std.algorithm, std.typecons, std.range, std.container, std.math, std.algorithm.searching, std.functional,std.mathspecial;
     
    void main(){
        auto NAB=readln.split.map!(to!int).array;
        auto Xs=readln.split.map!(to!long).array;
        auto res=0L;
        foreach(i;0..NAB[0]-1){
            res+=min(NAB[1]*(Xs[i+1]-Xs[i]),NAB[2]);
        }
        writeln(res);
    }