Help me in solving FIT problem

My issue

why we use T-- in while

My code

#include <iostream>
using namespace std;

int main() {
	// your code goes here
	int T;
	cin>>T;
	while(T--){
	    int x;
	    cin>>x;
	    cout<<10*x<<endl;
	}
	return 0;
}

Learning course: Basic Math using C++
Problem Link: CodeChef: Practical coding for everyone

@gauravpathak11
Its the test test case loop .
Like U have to take inputs and output T times.