#include <stdio.h>

size_t replace(char* text, char find, char replace)
{
	size_t count = 0;
	for ( ; *text; ++text )
		if ( *text == find )
		{
			*text = replace;
			++count;
		}

	return count;
}

int main(int argc, char* argv[])
{
	if ( argc <= 3 ) return fprintf(stderr, "Usage: replace a b texts\n");

	char find = *argv[1], repl = *argv[2];
	size_t count = 0;
	for ( int i = 3; i < argc; ++i )
	{
		count += replace(argv[i], find, repl);
		printf("%s ", argv[i]);
	}
	printf("\n%zi replaces\n", count);
	return 0;
}