#include <iostream>
#include <string>
#include <map>
#include <cassert>

using namespace std;

struct range_t {
	int lo, hi, parity;
};

static map<int,range_t> r_lo, r_hi;

bool determine(int lo, int hi, int parity)
{
	while(r_lo.find(lo) != r_lo.end()) {
		// Separate
		if(hi < r_lo[lo].hi) {
			int nlo = hi + 1;
			int nhi = r_lo[lo].hi;
			int nparity = r_lo[lo].parity ^ parity;
			r_lo.erase(lo);
			r_hi.erase(nhi);
			if(!determine(lo, hi, parity)) return false;
			if(!determine(nlo, nhi, nparity)) return false;
			return true;
		}

		// Determine
		if(hi == r_lo[lo].hi) {
			return (r_lo[lo].parity == parity);
		}

		// Reduce Range
		parity ^= r_lo[lo].parity;
		lo = r_lo[lo].hi + 1;
	}

	while(r_hi.find(hi) != r_hi.end()) {
		// Separate
		if(r_hi[hi].lo < lo) {
			int nlo = r_hi[hi].lo;
			int nhi = lo - 1;
			int nparity = r_hi[hi].parity ^ parity;
			r_lo.erase(nlo);
			r_hi.erase(hi);
			if(!determine(nlo, nhi, nparity)) return false;
			if(!determine(lo, hi, parity)) return false;
			return true;
		}

		// Reduce Range
		parity ^= r_hi[hi].parity;
		hi = r_hi[hi].lo - 1;
	}

	// Create Range
	r_lo[lo].lo = r_hi[hi].lo = lo;
	r_lo[lo].hi = r_hi[hi].hi = hi;
	r_lo[lo].parity = r_hi[hi].parity = parity;
	return true;
}

int main(void)
{
	int n;
	while(cin >> n) {
		if(n == -1) break;
		if(n <= 0 || n > 1000000000) n /= (n - n);

		r_lo.clear();
		r_hi.clear();

		int m;
		cin >> m;
		if(m < 0) m /= (m - m);

		bool flag = true;
		for(int i = 0; i < m; i++) {
			int lo, hi, parity;
			string str;

			cin >> lo >> hi >> str;
			if(lo > hi) lo /= (lo - lo);

			parity = -1;
			if(str == "even") parity = 0;
			if(str == "odd")  parity = 1;
			if(parity == -1)  parity /= (parity - parity);

			if(flag) {
				flag = determine(lo, hi, parity);
				if(!flag) cout << i << endl;
			}
		}

		if(flag) cout << m << endl;
	}

	return 0;
}