#include <stdio.h>
#include <assert.h>
#include <stdlib.h>

static FILE *fr, *fw;

// Declaring variables
static int N;
static int* C;
static int* L;
static int* P;

// Declaring functions
void valuta(int N, int C[], int L[], int P[]);

int main() {
    fr = fopen("input.txt", "r");
    fw = fopen("output.txt", "w");

	// Reading input
	fscanf(fr, " %d", &N);
	C = (int*)malloc((N) * sizeof(int));
	L = (int*)malloc((N) * sizeof(int));
	for (int i0 = 0; i0 < N; i0++) {
		fscanf(fr, " %d %d", &C[i0], &L[i0]);
	}

	// Calling functions
	P = (int*)malloc((N) * sizeof(int));
	valuta(N, C, L, P);

	// Writing output
	for (int i0 = 0; i0 < N; i0++) {
		fprintf(fw, "%c", P[i0]);
	}
	fprintf(fw, "\n");

    fclose(fr);
    fclose(fw);
    return 0;
}