Description
#include <cstdio>
using namespace std;
int a[1005] = {0}, b[1005] = {0};
int main() {
int i, j, k, n;
while(scanf("%d", &n) && n) {
while(scanf("%d", &b[0]) && b[0]) {
for(j = 1; j < n; j++)
scanf("%d", &b[j]);
for(i=1,j=0,k=0; i<=n&&j<n; i++,k++) {
a[k] = i;
while(a[k] == b[j]) {
if(k > 0)
k--;
else {
a[k] = 0;
k--;
}
j++;
if(k == -1)
break;
}
}
if(j == n)
printf("Yes\n");
else
printf("No\n");
}
printf("\n");
}
return 0;
}