USING if statement in C++

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */  
 int a;
    cin>>a;
    if(a>9){
        cout<<"Greater than 9";
    }
    else if(a==1){
        cout<<"one";
    }
    else if(a==2){
        cout<<"two";
    }
    else if(a==3){
        cout<<"three";
    }
    else if(a==4){
        cout<<"four";
    }
    else if(a==5){
        cout<<"five";
    }
    else if(a==6){
        cout<<"six";
    }
    else if(a==7){
        cout<<"seven";
    }else if(a==8){
        cout<<"eight";
    }else if(a==9){cout<<"nine";}else
        cout<<"invalid choice";
   return 0;
}