char* maximumBinaryString(char* binary) {
int n = strlen(binary);
int cnt = 0;
int mark = 0;
for(int i = 0; i < n; ++i){
if(binary[i] == '0') mark = 1;
if(mark && binary[i] == '1') cnt++;
}
if(cnt == 0 && mark == 0) return binary;
for(int i = 1; i <= n; ++i){
if(i == n - cnt) binary[i - 1] = '0';
else binary[i - 1] = '1';
}
return binary;
}