diff --git a/QUSTOJ/1756.c b/QUSTOJ/1756.c
new file mode 100644
index 0000000..28047cb
--- /dev/null
+++ b/QUSTOJ/1756.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+void replace(char* str,char a,char b)
+{
+    int L=strlen(str);
+    for(int i=0;i<L;i++)
+    {
+        if(str[i]==a) str[i]=b;
+    }
+}
+
+char msg[1024];
+int main()
+{
+    gets(msg);
+    char a,b;
+    scanf("%c,%c",&a,&b);
+    replace(msg,a,b);
+    printf("%s\n",msg);
+    return 0;
+}