how to use unordered map in c++

I am writing a program that uses unordered map. after some research prior to this, I know that to use unordered map, first we need to put header. but It didn't worked. thanks in advance for any tips. and oh ya this is the error message

 #error This file requires compiler and library support for the \
  ^
umap.cpp: In function 'int main()':
umap.cpp:21:2: error: 'unordered_map' was not declared in this scope
  unordered_map<string, int> siswa;
  ^
umap.cpp:21:22: error: expected primary-expression before ',' token
  unordered_map<string, int> siswa;
                      ^
umap.cpp:21:24: error: expected primary-expression before 'int'
  unordered_map<string, int> siswa;
                        ^
umap.cpp:24:2: error: 'siswa' was not declared in this scope
  siswa["saleh"]=90;
  ^

AND here's the program

#include <iostream>
#include <unordered_map>
#include <bits/stdc++.h> 

using namespace std;

void cari(string key){

    if(siswa.find(key)==siswa.end())
        cout<<siswa[key]<<endl;
    else
        cout<<"n/a"<<endl;
}


int main(){


    unordered_map<string, int> siswa;


    siswa["saleh"]=90;
    siswa["mutiara"]=85;
    siswa["icam"]=70;

    int t;
    cin>>t;
    string key;
    for(int i=0;i<t;i++){

        getline(cin,key);
        cari(key);
    }
}

btw, sorry for my messy grammar :v