C :

#include <stdio.h>
int main()
{
	char c;
    scanf("%c",c);
    if(c>='A'&&c<='Z')
    printf("false");
    else
    printf("true");
}

C++ :

#include<stdio.h>
void pro(char ch1)
{
    if(ch1>=65&&ch1<=90)
          printf("true\n");
    else printf("false\n");
}
 
int main()
{
   char ch;
   scanf("%c",&ch);
   pro(ch);
return 0;
}

Pascal :

program xx;
var ch:char;
begin
read(ch);
if(ord(ch)>=65) and(ord(ch)<=90)
  then writeln('true')
  else writeln('false');
end.