Erasing elements in vector array in C++

Vector erase question - click here

Solution :
Go to the description to see the answer as in the question, the things aren't proper and output isn't clear.
The question is 1-indexed.
Code :
#include<iostream>
#include<vector>
using namespace std;
int main(){
    vector<int> v;
    int size;
    int n;
    cin>>size;
    for(int i=0;i<size;i++){
        cin>>n;
        v.push_back(n);
    }
    int pos;
    cin>>pos;
    int a, b;
    cin>>a>>b;
    v.erase(v.begin()+pos-1);
    v.erase(v.begin()+a-1, v.begin()+b-1);
    cout<<v.size()<<endl;
    int x = v.size();
    for(int i=0;i<x;i++)
        cout<<v[i]<<" ";
    return 0;
}