#include<stdio.h>

int main(void){

int t,x;
char Ans = 'T';
int prev = 0;
int cal = 0;

scanf("%d",&t);
int i;
for(i = 0; i < t; i++){

  scanf("%d",&x);

  cal = x - prev;

  if(cal != 1 && cal != -1){
    Ans = 'F';
  }

    prev = x;

}

printf("%c\n",Ans);
return 0;
}