Getting Wrong Answer for FLOW007 problem

Codechef Problem - https://www.codechef.com/LRNDSA01/problems/FLOW007/

Why does this code give me wrong answer on submitting for the FLOW007 Problem

#include <iostream>
#include <algorithm>
using namespace std;

int main(){

  unsigned int t;
	unsigned int digit;
	cin>>t;
	while(t!=0){
	    cin>>digit;
	    string s = to_string(digit);
	    for(int i=s.length();i>=0;i--){
        cout<<s[i];
      }
	    cout<<endl;
	    t--;
	}
  return 0;
}

The o/p for 3200 should be 23 and your code is printing 0023.