import java.io.DataInputStream;
import java.io.IOException;
import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.lang.StringBuilder;
public class Labels {
static class Reader {
final private int BUFFER_SIZE = 1 << 16;
private DataInputStream din;
private byte[] buffer;
private int bufferPointer, bytesRead;
public Reader() {
din = new DataInputStream(System.in);
buffer = new byte[BUFFER_SIZE];
bufferPointer = bytesRead = 0;
}
public int nextInt() throws IOException {
int ret = 0;
Boolean flip = false;
byte c = read();
while (c < '0' || c > '9') {
if (c == '-') flip = true;
c = read();
}
do {
ret = ret * 10 + c - '0';
} while ((c = read()) >= '0' && c <= '9');
return flip ? -ret : ret;
}
private void fillBuffer() throws IOException
{
bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
if (bytesRead == -1) {
buffer[0] = -1;
}
}
private byte read() throws IOException
{
if (bufferPointer == bytesRead) {
fillBuffer();
}
return buffer[bufferPointer++];
}
}
public static void main(String[] args) throws IOException {
Reader reader = new Reader();
BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));
int N = reader.nextInt();
int D[] = new int[N+1];
int P[] = new int[N+1];
int maxn = 0, minn = 0;
for (int a = 0; a < N - 1; ++a) {
D[a] = reader.nextInt();
if (a>0) D[a] += D[a - 1];
maxn = Math.max(maxn, D[a]);
minn = Math.min(minn, D[a]);
}
if (maxn - minn != N - 1) {
System.out.println("-1");
System.exit(0);
}
P[0] = N - maxn;
for (int a = 1; a < N; ++a) P[a] = P[0] + D[a - 1];
for (int a = 0; a < N; ++a) {
out.write(Integer.toString(P[a]));
if (a == N - 1) out.write("\n");
else out.write(" ");
}
out.flush();
}
}
