import java.util.*;
import java.lang.*;
import java.io.*;
 
class PlusMinus {
	public static void main (String[] args) throws java.lang.Exception {
		Scanner read = new Scanner(System.in);
		int m = read.nextInt();
		int Z[] = new int [m];
		int count = 0;
		int sign = 0;
 
		for (int i = 0; i < m; i++){
	    	Z[i] = read.nextInt();
		}
 
		int i = 0;
		for(i = 0; (Z[i] == 0) && (i < m); i++ );
			sign = Z[i];
 
		for (int j = 0; j < m; j++) {
			if (sign * Z[j] < 0) {
				sign = Z[j];
				count ++;
			}
		}
		System.out.print("Число чередований знака = "+count);
	}
}

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MTEKMCAtMiAwIC0xMCAyIC0xIDAgMCAzIDIgLTMKMTMKMCAwIDAgIC0yIDAgLTEwIDIgLTEgMCAwIDMgMiAzCgo=

11
0 -2 0 -10 2 -1 0 0 3 2 -3
13
0 0 0  -2 0 -10 2 -1 0 0 3 2 3