// Codeforces Beta Round #62 D. Half-decay tree

#include <iostream>
#include <map>
#include <stdio.h>

using namespace std;

int h, q;
map<int, int> sum;

double calc(int v, double lower){
	if(sum[v] <= lower) return lower;
	if(v&(1<<h)) return max(lower, (double)sum[v]);
	double res = 0;
	for(int i=0;i<2;i++) res += calc(2*v+i, max(lower, (double)sum[v]-sum[2*v+i]));
	return 0.5*res;
}

int main(){
	while(cin >> h >> q){
		sum.clear();
		for(int Q=0;Q<q;Q++){
			char com[10]; scanf("%s", com);
			if(com[0] == 'a'){
				int idx, e; scanf("%d %d", &idx, &e);
				for(int i=idx;i>0;i/=2) sum[i] += e;
			} else {
				printf("%.8lf\n", calc(1,0));
			}
		}
	}
}