#include <cstdio>#include <cstring>#include <algorithm>#include <map>#include <set>#include <bitset>#include <queue>#include <stack>#include <string>#include <iostream>#include <cmath>#include <climits>using namespace std;const int maxn = 30;int a[maxn][maxn], fid[maxn], fcnt;void Gauss() {	for(int i = 0; i < 20; i++) {		int k = i;		while(a[k][i] == 0 && k < 20) k++;		if(k >= 20) continue;		for(int j = 0; j <= 20; j++) swap(a[i][j], a[k][j]);		for(int j = 0; j < 20; j++) if(i != j && a[j][i] != 0) {			for(int k = 0; k <= 20; k++) a[j][k] ^= a[i][k];		}	}}void pa() {	for(int i = 0; i < 20; i++) {		for(int j = 0; j <= 20; j++) {			printf("%d ", a[i][j]);		}		puts("");	}}int main() {	while(1) {		memset(a, 0, sizeof(a));		for(int i = 0; i < 20; i++) {			int ret = scanf("%d", &a[i][20]);			if(ret == EOF) return 0;		}		for(int i = 0; i < 20; i++) {			a[i][i] = a[i][max(i - 1, 0)] = a[i][min(i + 1, 19)] = 1;		}		Gauss();		fcnt = 0;		memset(fid, -1, sizeof(fid));		for(int i = 0; i < 20; i++) {			int nowsum = 0;			for(int j = 0; j <= 20; j++) nowsum += a[i][j];			if(nowsum == 0) fid[i] = fcnt++;		}		int ans = 1e9;		for(int i = 0; i < (1 << fcnt); i++) {			int nowans = 0;			for(int j = 0; j < 20; j++) {				int nows = 0;				for(int k = 0; k < 20; k++) if(fid[k] != -1 && a[j][k]) {					if((1 << fid[k]) & i) nows ^= 1;				} 				if(nows != a[j][20]) nowans++;			}			int bcnt = 0;			for(int j = 0; j < fcnt; j++) if(i & (1 << j)) bcnt++;			ans = min(ans, nowans + bcnt);		}		printf("%d\n", ans);	}	return 0;}