#include <stdio.h>

int main(int argc, char *argv[]) {

	int c, i;
	float total = 0.0;
	float freq;

	// initialize our 26 counters to zero
	float char_count[26];
	for (i = 0; i < 26; i++) {
		char_count[i] = 0.0;
	}

	// open our file
	FILE *f = fopen(argv[1], "r");
	
	while ( !feof(f) ) {
	
		// check each character in the file
		c = fgetc(f);
		if ( (c >=65) && (c <= 90) ) {

			// upper case letter
			char_count[c - 65] += 1.0;
			total += 1.0;
		}
		else if ( (c >= 97) && (c <= 122) ) {
		
			// lower case letter
			char_count[c - 97] += 1.0;
			total += 1.0;
		}
	
	}
	fclose(f);
	
	// calculate the frequency of each character and print the result
	for (i = 0; i < 26; i++) {
		freq = char_count[i] / total * 100.0;
		printf("%c: %.2f\n", (char)(i + 97), freq);
	}
}