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

int main(int argc, char const *argv[])
{
    FILE* input = fopen("input", "r");
    FILE* output = fopen("output", "w");
    int m;
    int n;
    fscanf(input, "%d", &m);
    while((fscanf(input, "%d", &n) > 0) && (n != EOF)) {
        if (n > m) {
            m = n;
        }
    }
    fprintf(output, "%d\n", m);
    fclose(input);
    fclose(output);
    return 0;
}