#include<cstdio>
#include<iostream>
#include<string.h>
#include<vector>
#define MAXN 55
typedef long long ll;
using namespace std;
char str[55];
int dp[MAXN][MAXN]={0};
int min(const int &a,const int &b){
return a<b?a:b;
}
int main(){
#ifdef local
freopen("data0.in","rb",stdin);
//freopen("data.out","wb",stdout);
#endif
scanf("%s",str);
int n=strlen(str);
fill(dp[0],dp[0]+MAXN*MAXN,MAXN);
for(int i=0;i<n;++i){
dp[i][i]=1;
}
for(int len=2;len<=n;++len){
for(int i=0;i<n+1-len;++i){
int j=i+len-1;
if(str[i]==str[j]){
dp[i][j]=min(dp[i][j-1],dp[i+1][j]);
}
else{
for(int k=i;k<j;++k){
if(dp[i][j]>dp[i][k]+dp[k+1][j])
dp[i][j]=dp[i][k]+dp[k+1][j];
}
}
}
}
cout<<dp[0][n-1];
return 0;
}
08-08
163

07-05
111

11-13
284
