#include<iostream>
using namespace std;
char c, last, last_zn;
int br;
int main()
{
    cin.get(last);
    if(last>='a'&&last<='z') br++;
    while(cin.get(c))
    {
      if(((last_zn=='.')||(last_zn=='!')||(last_zn=='?'))&&((c>='A')&&(c<='Z'))) last_zn=' ';
      if(((last_zn=='.')||(last_zn=='!')||(last_zn=='?'))&&((c>='a')&&(c<='z'))) { /*cout<<c<<endl;*/ br++; last_zn=' '; }
      if(((last>='a'&&last<='z')||(last>='A'&&last<='Z'))&&(c>='A'&&c<='Z')) { /*cout<<c<<endl;*/ br++; }
      last=c;
      if((c=='.')||(c=='?')||(c=='!')) last_zn=c;
    }
    cout<<br<<endl;
    return 0;
}


I tried all the tests here and none of them gave me WA. Can you tell me where is my mistake???