#include <stdio.h>
#include <stdlib.h>

int main(){
    int n,i,dot_n=0,sharp_n=0,dot_l=-1, dot_r = -1,sharp_r = -1;
    char *s;

    scanf("%d", &n);
    s = malloc(sizeof(char)*(n+1));
    scanf("%s", s);
    for(i=n-1;i>=0;i--){
        if(s[i] == '#'){
            sharp_r = i;
        }else{
            dot_n++;
        }
    }
    if(sharp_r == -1){
        printf("0\n");
        return 0;
    }
    for(i=sharp_r;i>=0;i--){
        if(s[i] == '.'){
            dot_r = i;
        }
    }
    if(dot_r == -1){
        printf("%d\n", dot_n);
        return 0;
    }

    for(i=0;i<sharp_r;i++){
        if(s[i] == '#'){
            dot_l = i;
            break;
        }
    }
    if(dot_l == -1){
        printf("%d\n",dot_n);
        return 0;
    }

    for(i=dot_l;i<=dot_r;i++){
        if(s[i] == '#'){
             sharp_n = i;
            break;
        }
    }

    printf("%d\n",dot_n+sharp_n);



    return 0;

}