import java.util.*;
public class Solution {
/**
* 解码
* @param nums string字符串 数字串
* @return int整型
*/
public int solve (String nums) {
// write code here
if (nums.charAt(0) == '0') return 0;
if (nums == "10" || nums == "20") return 1;
for (int i = 1; i < nums.length(); i++){
if (nums.charAt(i) == '0' && (nums.charAt(i - 1) != '1' && nums.charAt(i - 1) != '2')) return 0;
}
int[] dp = new int[nums.length() + 1];
Arrays.fill(dp, 1);
for (int i = 2; i <= nums.length(); i++){
if ((nums.charAt(i - 2) == '1' && nums.charAt(i - 1) != '0') || (nums.charAt(i - 2) == '2' && nums.charAt(i - 1) != '0' && nums.charAt(i - 1) < '7')){
dp[i] = dp[i - 1] + dp[i - 2];
} else{
dp[i] = dp[i - 1];
}
}
return dp[nums.length()];
}
}